Interactive input system having a 3d input space

ABSTRACT

Computerized methods and interactive input systems for manipulation of 3D objects are disclosed. An image of 3D object is displayed on a 2D interactive surface, and input is received and is interpreted for manipulating the 3D object. When the 3D object is selected, rotation control handles indicating available rotation directions are displayed. In one embodiment, the method comprises capturing images of a 3D input space, recognizing at least one object in the images, and comparing the recognized objects in the images to determine a difference therebetween based on a difference threshold. Depending on the outcome of the comparison, the recognized objects are emerged and associated with digital content, or only one of the recognized objects is maintained and associated with digital content.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/389,016 to Xin et al. filed on Oct. 1, 2010, entitled “Stereoscopic3D Input System and Method for Manipulating Graphic Objects” and U.S.Provisional Application No. 61/450,032 to Lai et al. filed on Mar. 7,2011, entitled “Stereoscopic 3D Input System, Tools Therefor and Methodsfor Manipulating Graphic Objects”, the contents of which areincorporated herein by reference in their entireties. This applicationis also related to U.S. Provisional Application No. 61/365,757 toAntonyuk et al. filed on Jul. 19, 2010, entitled “Interactive InputSystem Having A 3D Input Space”, U.S. Provisional Application No.61/371,975 to Xin et al. filed on Aug. 9, 2010, entitled “InteractiveInput System Having A 3D Input Space” and U.S. Provisional ApplicationNo. 61/431,850 to Tse et al. filed on Jan. 12, 2011, entitled“Interactive Input System Having 3D Input Space”, the contents of whichare incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates generally interactive input systems and inparticular, to an interactive input system having a 3D input space andto computerized methods.

BACKGROUND OF THE INVENTION

“Mixed reality” generally refers to the merging of real and virtualworlds to produce new environments and visualisations in which physicaland digital objects co-exist and interact in real time. Interactiveinput systems that utilize mixed reality, often referred to as“augmented interactive input systems”, are known in the art. Someexisting augmented interactive input systems make use of a documentcamera to track physical objects such as cubes and flashcards thatcomprise recognizable patterns. Digital content is superimposed on topof the images captured by the document camera. Direct association of thephysical objects to digital content allows users to manipulate thedigital content through manipulation of the physical objects.

Stereoscopic three-dimensional (3D) input systems have also beenconsidered. For example, U.S. Patent Application Publication No.2008/0094398 to Ng et al. discloses a 3D visualization system that canbe ported to a laptop or desktop personal computer (PC), or otherstandard two-dimensional (2D) computing environment, which uses a mouseand keyboard as user input devices. A cursor or icon can be drawn at acontextually appropriate depth, thus preserving 3D interactivity andvisualization while only having available 2D control. A spatiallycorrect depth can be automatically found for, and assigned to, thecursors and icons associated with various 3D tools, control panels andother manipulations. This can preserve the 3D experience of interactingwith a 3D data set even though the 2D interface used to select objectsand manipulate them cannot directly provide a third dimensionalco-ordinate. Based upon the assigned position of the cursor or icon in3D, the functionality of a selected tool, and whether and in whatsequence any buttons have been pressed on a 2D interface device, avariety of 3D virtual tools and functionalities can be implemented andcontrolled by a standard 2D computer interface.

U.S. Patent Application Publication No. 2006/0012675 to Alpasian et al.discloses an apparatus and method for 3D interaction with anautostereoscopic display. A motion tracking system may include videocameras that track a 3D motion of a user within an interaction volumedefined by the fields-of-view of the video cameras, as the user moves alight source or other optical marker or an anatomical region of the userwithin the interaction volume. The motion tracking system may generate3D tracking data containing position information about the 3D motion. Animaging system may create a virtual scene by tracing 3D virtual objectsin virtual space, using the position information in the 3D trackingdata. The imaging system may synthesize a plurality of views of thevirtual scene, and interlace the plurality of views to generate aninterlaced image to drive the autostereoscopic display and to bedisplayed thereon.

A disadvantage of known augmented interactive input systems is thetemporary loss of physical objects that are being tracked. Thistypically occurs when a recognizable pattern on the object is partiallyor completely obscured, such as by fingers or hands during manipulationof the physical object in a 3D input space. This can also occur when therecognizable pattern is out of the field of view of the camera, due to aparticular orientation of the physical object in relation to the fieldof view of the camera. When the augmented interactive input systemtemporarily loses track of the recognizable pattern and then regainstracking of the recognizable pattern, the associated digital contentshown on the display disappears momentarily and then re-appears, causingthe display to flicker.

Additionally, while some known augmented interactive input systems allowmanipulation of recognized image objects from a printed medium, such aspaper, these systems do not provide any means of visual feedback on thepaper to facilitate manipulation of the recognized image objects.

Improvements are generally desired. It is therefore an object of thepresent invention at least to provide novel interactive input systemsand novel computerized methods.

SUMMARY OF THE INVENTION

Accordingly, in one aspect there is provided a computerized methodcomprising: displaying a two-dimensional (2D) image of athree-dimensional (3D) object on a display; defining at least one regionon said display for controlling the rotation of said 3D object about adefined axis, said axis being parallel to a display surface of saiddisplay; receiving input applied to said at least one region;determining, from said input, a rotation direction; and modifying saiddisplayed 2D image by rotating said 3D object about the defined axisalong said rotation direction.

According to another aspect, there is provided an interactive inputsystem comprising: a display comprising a display surface on which atwo-dimensional (2D) image of a three-dimensional (3D) object and atleast one region for controlling rotation of said 3D object about adefined axis are presented; and computing structure communicating withsaid display, said computing structure, in response to input applied tosaid at least one region, determining a rotation direction and modifyingsaid 2D image by rotating said 3D object about said defined axis in saidrotation direction.

According to another aspect, there is provided an interactive inputsystem comprising: computing structure; a display in communication withsaid computing structure, said display presenting an image comprisingdigital content; and an input device detecting at least one physicalobject carrying a recognizable pattern within a three-dimensional (3D)input space and providing output to said computing structure, saidcomputing structure being configured to process the output of the inputdevice to: recognize the pattern carried by the at least one physicalobject in the 3D input space; and modify the image presented on thedisplay based on at least one of the detected state of the at least onephysical object and the proximity of a user to a designated location.

According to yet another aspect, there is provided a computerized methodcomprising: presenting an image comprising digital content on a displaysurface; recognizing a pattern carried by a physical object placedwithin a three-dimensional input space; and modifying the image based onat least one of the detected state of the at least one physical objectand proximity of a user to a designated location.

According to yet another aspect, there is provided a computerized methodcomprising: displaying an enclosure around the periphery of a displayedgraphic object upon selection of the graphic object, the enclosurehaving control elements associated therewith; and manipulating thegraphic object according to user interaction with at least one of saidcontrol elements.

According to yet another aspect, there is provided an interactive inputsystem comprising: a display comprising a display surface on which atleast one graphic object is presented; and computing structurecommunicating with said display, said computing structure beingconfigured to cause said display to present an enclosure having controlelements associated therewith around the periphery of a selected graphicobject and to manipulate the graphic object according to userinteractions with at least one control element of said enclosure.

According to yet another aspect, there is provided a computerized methodcomprising: designating one or more anchor points on a displayed graphicobject; anchoring a label box to one or more said anchor points; andannotating said label box.

According to yet another aspect, there is provided an interactive inputsystem comprising: a display comprising a display surface; and computingstructure communicating with said display, said computing structurebeing configured to: designate one or more anchor points on a graphicobject presented on said display surface; anchor a label box to one ormore said anchor points; and annotate said label box.

According to yet another aspect, there is provided a computerized methodcomprising: capturing an image of a three-dimensional (3D) input spaceand recognizing at least one object therein; capturing another image ofsaid 3D input space and recognizing at least one object therein;comparing the captured images to determine a difference therebetween;when said difference is greater than a difference threshold, merging therecognized objects to form a composite recognized object and storingsaid composite recognized object; when said difference is not greaterthan said difference threshold, storing one of said recognized objectsand discarding the other of said recognized objects; and associatingeither said stored composite recognized object or said stored onerecognized object with digital content.

According to yet another aspect, there is provided an interactive inputsystem comprising: an input device capturing images of athree-dimensional (3D) input space; and computing structurecommunicating with said input device, said computing structure beingconfigured to: recognize at least one object in captured images; comparecaptured images to determine differences therebetween; when saiddifferences are greater than a difference threshold, merge therecognized objects to form a composite recognized object and store saidcomposite recognized object; when said differences are not greater thansaid difference threshold, store one of said recognized objects anddiscard the remaining recognized objects; and associate either saidstored composite recognized object or said stored one recognized objectwith digital content.

According to yet another aspect, there is provided a computerized methodcomprising: capturing images of a three-dimensional (3D) input space;recognizing at least one object in each image; comparing a pair of saidimages to determine a difference therebetween; when said difference isgreater than a difference threshold, merging said recognized objects andassociating digital content therewith; and when said difference is notgreater than said difference threshold, maintaining at least onerecognized object from only one of said images in said pair andassociating digital content therewith.

According to yet another aspect there is provided an interactive inputsystem comprising: computing structure; and an input device capturing animage of at least one physical object carrying recognizable text withina three-dimensional (3D) input space and providing image data to saidcomputing structure, wherein said computing structure processes theimage data and is configured to: present said image on a display coupledto said computing structure; recognize at least one object carried bythe at least one physical object in the 3D input space; associate atleast a portion of said recognized at least one object with a link todigital content; receive user input representing activation of saidlink; and superimpose said digital content on said image.

According to yet another aspect there is provided a computerized methodcomprising: presenting an image on a display coupled to computingstructure; recognizing at least one object carried by at least onephysical object in a three-dimensional (3D) input space; associating atleast a portion of said recognized at least one object with a link todigital content; receiving user input representing activation of saidlink; and superimposing said digital content on said image.

According to still yet another aspect there is provided an imagecapturing apparatus comprising: computing structure; a camera devicecapturing images of a three-dimensional (3D) input space coupled to saidcomputing structure, wherein said 3D input space comprises atwo-dimensional (2D) plane; and light projection structure coupled tosaid computing structure, said computing structure receiving imagescaptured by said input device, recognizing objects within said images,associating recognized objects with digital content, and projecting saiddigital content to said 2D plane, wherein said digital content ismanipulatable on said 2D plane.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described more fully with reference to theaccompanying drawings in which:

FIG. 1A is a perspective diagram of an interactive input system having athree-dimensional (3D) input space;

FIG. 1B is a perspective view of a 3D input device forming part of theinteractive input system of FIG. 1A showing the 3D input space imagedthereby;

FIG. 2 is a schematic diagram showing a software architecture of theinteractive input system of FIG. 1A;

FIGS. 3A and 3B illustrate translation of a 3D object on atwo-dimensional (2D) interactive surface forming part of the interactiveinput system of FIG. 1A, in a 2D translation mode;

FIGS. 4A and 4B illustrate translation of a 3D object on the 2Dinteractive surface of FIGS. 3A and 3B, in a 3D translation mode;

FIG. 5 illustrates a selection box for manipulating a 3D object on the2D interactive surface;

FIGS. 6A to 6C illustrate resizing of a 3D object using a resizingcontrol handle of the selection box of FIG. 5;

FIGS. 7A to 7D illustrate rotation of a 3D object about the z-axis usinga z-rotation control handle of the selection box of FIG. 5;

FIGS. 8A to 8D illustrate rotation of a 3D object about the y-axis usingy-axis slider control handles of the selection box of FIG. 5;

FIGS. 9A to 9D illustrate rotation of a 3D object about the x-axis usingx-axis slider control handles of the selection box of FIG. 5;

FIGS. 10A to 10D illustrate rotation of a 3D object using an arc ballfree rotation tool of the selection box of FIG. 5;

FIGS. 11A to 11E show a flowchart of the steps performed duringmanipulation of a 3D object on the 2D interactive surface;

FIGS. 12A to 12C illustrate an alternative selection box formanipulating a 3D object on the 2D interactive surface;

FIGS. 13A and 13B illustrate another alternative selection box formanipulating a 3D object on the 2D interactive surface;

FIGS. 14A to 14F illustrate yet another alternative selection box formanipulating a 3D object on the 2D interactive surface;

FIGS. 15A to 15D illustrate yet another alternative selection box formanipulating a 3D object on the 2D interactive surface;

FIG. 16 is a flowchart showing the steps performed during manipulationof a 3D object using the selection box of FIGS. 15A to 15D;

FIG. 17 is a flowchart showing the steps performed during a 3D objectlabelling and annotating method;

FIGS. 18A and 18B illustrate label boxes and anchor points on a 3Dobject;

FIG. 19 is a flowchart showing the steps performed during a 3D objectlabel box display method;

FIG. 20 is a schematic diagram showing an alternative softwarearchitecture of the interactive input system of FIG. 1A;

FIG. 21 is a flowchart showing the steps performed during manipulationof digital content associated with recognized objects of print matter inthe 3D input space;

FIGS. 22A to 22C illustrate recognition of textual objects of the printmatter, and association of digital content therewith;

FIGS. 23A to 23C illustrate recognized digital content superimposed onan image of the print matter, and selection of the digital content;

FIGS. 24A to 24C illustrate manipulation of a 3D object superimposed onthe print matter image;

FIGS. 25A and 25B illustrate a resizing gesture of the print matterimage;

FIG. 26 illustrates digital content superimposed on an image ofalternative print matter in the 3D input space;

FIGS. 27A and 27B illustrate selection of recognized text superimposedon the print matter image;

FIG. 28 illustrates execution of a calculator application program uponselection of recognized text superimposed on the print matter image;

FIGS. 29A and 29B illustrate manipulation of a 3D object superimposed onan alternative print matter image;

FIGS. 30A and 30B illustrate another embodiment of a 3D input deviceforming part of the interactive input system of FIG. 1A;

FIG. 31 is a perspective view of a stereoscopic 3D interactive inputsystem having a 3D input space, according to another embodiment;

FIG. 32 is a schematic diagram showing the software architecture of thestereoscopic 3D interactive input system of FIG. 31;

FIGS. 33A to 33D illustrate manipulation of 3D content using touchdetection;

FIG. 34 is a flowchart showing the steps performed during manipulationof 3D content using proximity detection;

FIGS. 35A to 35D illustrate manipulation of 3D content using stereotractor beam interaction;

FIGS. 36A and 36B illustrate manipulation of 3D content using proximitydetection; and

FIG. 37 is a perspective view of a dual display stereoscopic 3Dinteractive input system, according to another embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Turning now to FIG. 1A, an interactive input system having athree-dimensional (3D) input space is shown and is generally identifiedby reference numeral 20. Interactive input system 20 allows a user toinject input such as digital ink, mouse events, commands, etc. into anexecuting application program. In this embodiment, interactive inputsystem 20 comprises a two-dimensional (2D) input device in the form ofan interactive board 22 mounted on a vertical support surface such asfor example, a wall surface or the like. Interactive board 22 comprisesa generally planar, rectangular 2D interactive surface 24 that issurrounded about its periphery by a bezel 26. A boom assembly 32 is alsomounted on the support surface above the interactive board 22. Boomassembly 32 supports a short-throw projector 38 such as that sold bySMART Technologies ULC of Calgary, Alberta, assignee of the subjectapplication, under the name “SMART Unifi 45”, which projects an image,such as for example, a computer desktop, onto the 2D interactive surface24. For ease of discussion, a 3D coordinate system 100 of theinteractive board 22 is referred to throughout this description. Theorigin of the 3D coordinate system 100 is coincident with the upper-leftcorner of the 2D interactive surface 24. The x-axis of the 3D coordinatesystem extends in the horizontal direction to the right, the y-axisextends in the vertical direction downwardly, and the z-axis extends inan outward direction perpendicular to the x-y plane. The 2D interactivesurface 24 of the interactive board 22 is therfore coincident with thex-y plane at z=0.

The interactive board 22 employs machine vision to detect one or morepointers brought into a region of interest in proximity with the 2Dinteractive surface 24. The interactive board 22 communicates with ageneral purpose computing device 28 executing one or more applicationprograms via a universal serial bus (USB) cable 30 or other suitablewired or wireless communication link. Computing device 28 processes theoutput of the interactive board 22 and adjusts image data that is outputto the projector 38, if required, so that the image presented on the 2Dinteractive surface 24 reflects pointer activity. In this manner, theinteractive board 22, computing device 28 and projector 38 allow pointeractivity proximate to the 2D interactive surface 24 to be recorded aswriting or drawing or used to control execution of one or moreapplication programs executed by the computing device 28.

The bezel 26 is mechanically fastened to the 2D interactive surface 24and comprises four bezel segments that extend along the edges of the 2Dinteractive surface 24. In this embodiment, the inwardly facing surfaceof each bezel segment comprises a single, longitudinally extending stripor band of retro-reflective material. To take best advantage of theproperties of the retro-reflective material, the bezel segments areoriented so that their inwardly facing surfaces lie in a plane generallynormal to the plane of the 2D interactive surface 24.

A tool tray 48 is affixed to the interactive board 22 adjacent thebottom bezel segment using suitable fasteners such as for example,screws, clips, adhesive etc. As can be seen, the tool tray 48 comprisesa housing having an upper surface configured to define a plurality ofreceptacles or slots. The receptacles are sized to receive one or morepen tools 40 as well as an eraser tool (not shown) that can be used tointeract with the 2D interactive surface 24. Control buttons (not shown)are also provided on the upper surface of the tool tray housing toenable a user to control operation of the interactive input system 20.

Imaging assemblies (not shown) are accommodated by the bezel 26, witheach imaging assembly being positioned adjacent a different corner ofthe bezel. Each of the imaging assemblies comprises an image sensor andassociated lens assembly that provides the image sensor with a field ofview sufficiently large as to encompass the entire 2D interactivesurface 24. A digital signal processor (DSP) or other suitableprocessing device sends clock signals to the image sensor causing theimage sensor to capture image frames at the desired frame rate. Duringimage frame capture, the DSP also causes an infrared (IR) light sourceto illuminate and flood the region of interest over the 2D interactivesurface 24 with IR illumination. Thus, when no pointer exists within thefield of view of the image sensor, the image sensor sees theillumination reflected by the retro-reflective bands on the bezelsegments and captures image frames comprising a continuous bright band.When a pointer exists within the field of view of the image sensor, thepointer occludes reflected IR illumination and appears as a dark regioninterrupting the bright band in captured image frames.

The imaging assemblies are oriented so that their fields of view overlapand look generally across the entire 2D interactive surface 24. In thismanner, any pointer such as for example a user's finger, a cylinder orother suitable object, or a pen or eraser tool lifted from a receptacleof the tool tray 48, that is brought into proximity of the 2Dinteractive surface 24 appears in the fields of view of the imagingassemblies and thus, is captured in image frames acquired by multipleimaging assemblies. When the imaging assemblies acquire image frames inwhich a pointer exists, the imaging assemblies convey pointer data tothe computing device 28.

The general purpose computing device 28 in this embodiment is a personalcomputer or other suitable processing device comprising, for example, aprocessing unit, system memory (volatile and/or non-volatile memory),other non-removable or removable memory (e.g. a hard disk drive, RAM,ROM, EEPROM, CD-ROM, DVD, flash memory, etc.) and a system bus couplingthe various computer components to the processing unit. The computingdevice 28 may also comprise networking capabilities using Ethernet,WiFi, and/or other suitable network format, to enable connection toshared or remote drives, one or more networked computers, or othernetworked devices. The computing device 28 processes pointer datareceived from the imaging assemblies and computes the location of anypointer proximate the 2D interactive surface 24 using well knowntriangulation. The computed pointer location is then recorded as writingor drawing or used as an input command to control execution of anapplication program as described above.

The interactive input system 20 also comprises a three-dimensional (3D)input device 52 that communicates with the computing device 28 via a USBcable 50. Those skilled in the art will understand that alternativewired connections, such as for example VGA, DVI, HDMI and the like orsuitable wireless connections to connect the 3D input device 52 to thecomputing device 28 may be employed. The 3D input device 52 comprises acamera 54 mounted to a base 58 via an articulated arm 56. The camera 54has a field of view that looks into a 3D input space 60. The 3D inputspace 60 defines a volume within which a physical object or marker froma set of markers may be positioned and manipulated. FIG. 1B shows amarker 62 positioned in the 3D input space 60. For ease of illustration,only the camera 54 of the 3D input device 52 is shown. In thisembodiment, the 3D input space 60 has the shape of a pyramidal frustumcomprising six (6) boundary surfaces, namely front, back, left, rightand top boundary surfaces 70 to 78, respectively, and bottom boundarysurface 80. The boundary surfaces 70 to 78 may be used to defineclipping planes for detection of clipping plane gestures, as describedin above-incorporated applications. The images captured by the camera 54are pre-processed by control circuitry (not shown) in the base 58 toadjust the brightness, clarity and/or resolution of the images, prior tobeing sent to the computing device 28.

In this embodiment, each marker of the set is in the form of a planarcard having a pattern printed or otherwise applied to at least onesurface thereof, or a cube with at least one surface having a patternprinted or otherwise applied thereto. The pattern comprises arectangular dark or black box having an arrangement of smaller light orwhite blocks thereon. The arrangement of smaller white blocks on thelarger black box is unique to each marker. This allows each marker to beassociated with different digital content and/or with a differentdigital content manipulation. “Digital content” herein refers to anytype of digital object, as opposed to a physical object, that ismaintained in the computing device 28 and that is represented by animage (e.g. a picture, an icon, an animation, and the like) displayed onthe 2D interactive surface 24. The digital content 64 may be any oftext, images, video clips, audio clips, animations and 3D objects, forexample. In the embodiment shown in FIG. 1A, the marker 62 is associatedwith digital content 64 in the form of a 3D graphic object representinga stadium.

“Digital tool” described herein refers to a digital content manipulationtool that is associated with a marker 62 for selecting or manipulatingdigital content. For example, a marker 62 may be predefined as aselection tool for selecting a 3D object. When the computing device 28detects that the marker 62 has performed a gesture for selecting a 3Dobject, the computing device 28 then associates the 3D object with theselection tool marker 62 so that the user may manipulate the 3D objectby manipulating the selection tool marker 62 in the 3D input space 60.Details of selecting digital content using selection tools are disclosedin one or more of the above-incorporated applications, and will not bedescribed further herein.

When the marker 62 positioned in the 3D input space 60 is captured in animage acquired by the camera 54, after the image has been pre-processedand converted into digital form by the control circuitry in the base 58and then conveyed to the computing device 28, the computing device 28processes the image to recognize the pattern. Once recognized, thecomputing device 28 determines the digital content object 64 associatedwith the recognized pattern. Thereafter, the computing device 28, usinga position mapping rule, combines the captured image, the digitalcontent object 64 associated with the recognized pattern on the markerand the graphical interface of the executing application program andoutputs the resultant image data to the projector 38 for presentation onthe 2D interactive surface 24. In this case, the digital content object64 is superimposed on the captured image and graphical interface. Thus,an image comprising both the real-world and digital content is displayedon the 2D interactive surface 24. Users of the interactive input system20 may manipulate the marker 62, e.g., by moving, rotating or tiltingthe marker 62 within the 3D input space 60, to interact with andmanipulate the digital content displayed on the 2D interactive surface24. For example, a user may rotate the marker 62 to rotate the digitalcontent object 64 and view it from different vantage points as desired.Details of detecting and manipulating markers are disclosed in one ormore of the above-incorporated applications.

The interactive input system 20 uses an event based mechanism to receiveuser input, which may be generated by manipulation of a marker 62 withinthe 3D input space 60, the 2D interactive surface 24 or from other inputdevices such as, for example, a keyboard, a mouse, a trackball, an audioinput device, a touchpad, a slate, and the like. In this embodiment, thecomputing device 28 monitors the 3D input space 60 by analyzing theimages captured by the 3D input device 52. The computing device 28detects markers 62 in the aforementioned pre-processed image,superimposes digital content on the image for display on the 2Dinteractive surface 24, and modifies the superimposed digital contentbased on the positions of the markers in the 3D input space 60. Thecomputing device 28 also detects pointers, such as for example fingersand styli, in the aforementioned pre-processed image, determines pointergestures according to the movement of the pointers, and generates 3Dinput events. The computing device 28 receives touch events from the 2Dinteractive surface 24, determines touch gestures, and generates 2Dinput events. The computing device 28 also receives input events fromother input devices such as, for example, a keyboard or a mouse. Thereceived input events are sent to respective application programsexecuted by the computing device 28 which interpret the user input asvarious commands such as for example, digital ink annotation commands,object manipulation commands or program control commands.

In this embodiment, the computing device 28 runs a host softwareapplication such as SMART Notebook™ offered by SMART Technologies ULC.As is known, during execution, the SMART Notebook™ application providesa graphical user interface comprising a canvas page or palette, that isoutput to the projector 38 and presented on the 2D interactive surface24, and on which freeform or handwritten ink objects together with othercomputer generated objects can be input and manipulated via pointerinteraction with the 2D interactive surface 24. Users may insert ordelete canvas page, or move to another canvas page by applying commandsto the SMART Notebook™ application window. For example, a user may clicka “forward” tool button in the application window to move to the nextcanvas page.

The SMART Notebook™ application allows users to insert digital contentobjects onto a canvas page, and to manipulate the digital contentobjects thereon by interacting with the 2D interactive surface 24 or byusing other input devices such as for example, a mouse or a keyboard.The SMART Notebook™ application also provides a mixed reality (MR) modein a canvas page, and allows users to manipulate them by using one ormore markers 62 brought into the 3D input space 60.

FIG. 2 shows a software architecture used by the interactive inputsystem 20, which is generally indicated using reference numeral 90. Thesoftware architecture 90 comprises an image processing module 92, a 3Dmanipulation module 94, and a 2D manipulation module 96. The imageprocessing module 92 comprises functions for pre-processing imagescaptured by the 3D input device 52. The pre-processing functionscomprise, for example, adjusting any of the brightness, the clarity andthe resolution of the images, and correcting any optical distortions.The image processing module 92 also superimposes digital content on theimages obtained from the 3D input device 52, for display on the 2Dinteractive surface 24. The image processing module 92 also modifies theimage displayed on the 2D interactive surface 24 based on input receivedfrom the 2D interactive surface 24 and from the 3D input space 60.

After the interactive input system 20 starts and the 3D input device 52is switched on, the camera 54 of the 3D input device is set to alow-resolution mode with a slow frame rate so that the camera 54captures a low-resolution image of the 3D input space 60 at regularintervals, such as for example every three (3) seconds. The imageprocessing module 92 then processes the captured images, during whichthe image processing module 92 determines whether marker patterns existwithin the captured images, and whether such marker patterns arerecognizable. If one or more patterns are recognizable, the computingdevice 28 instructs the camera 54 to change to a high-resolution modewith a high frame rate, and turns the MR mode on.

Captured high-resolution images are sent from the image processingmodule 92 to the 3D manipulation module 94, which recognizes patterns onmarkers, associates digital content or tools with recognized patterns,and identifies any user gestures based on user input in the 3D inputspace 60. The identified user gestures are then used to manipulate thedigital content accordingly. Similarly, the 2D manipulation module 96receives user input from the 2D interactive surface 24, and identifiesany user gestures for subsequent manipulation of the digital content 64.As will be appreciated, a user may therefore manipulate digital contentby applying gestures in the 3D input space 60 and/or applying gestureson the 2D interactive surface 24.

In this embodiment, a 3D scene, such as for example a SMART Notebook™canvas page comprising 3D objects, may be conditioned to either a 2Dtranslation (movement) mode or to a 3D translation mode. When a 3D sceneis conditioned to the 2D translation mode, dragging a 3D object (i.e.,applying a pointer to contact the 2D interactive surface 24 on the imageof the 3D object, and moving the pointer while maintaining the pointercontact thereon) to a different location on the 2D interactive surface24 causes the 3D object to be updated in a 2D manner, namely the 3Dobject is moved without changing its perspective, as if it were a 2Dobject. When a 3D scene is conditioned to the 3D translation mode,dragging a 3D object to a different location on the 2D interactivesurface 24 causes the 3D object to be updated in a 3D manner, namely theperspective of the 3D object changes as if it were being moved in a 3Dspace.

FIGS. 3A and 3B show an example of a 3D object 120 being moved in the 2Dtranslation mode. In this embodiment, the 2D translation mode is thedefault translation mode and does not need to be selected. In FIG. 3A, apointer 122 corresponding to a user's finger touches the 3D object 120on the 2D interactive surface 24, and drags the 3D object 120 to theright, as indicated by the arrow 124. In FIG. 3B, the pointer 122 hascompleted dragging the 3D object 120 on the 2D interactive surface 24.Although the 3D object 120 has been moved to a different location, itsperspective has not changed.

FIGS. 4A and 4B show an example of a 3D object 126 being moved in the 3Dtranslation mode. To select this mode, a camera icon 128 forming part ofa toolbar (not shown) displayed on the 2D interactive surface 24 isdragged from the toolbar and dropped to a position on the 2D interactivesurface 24. The interactive input system 20 system uses the (x, y)coordinates of the icon 128 on the 2D interactive surface 24 and apredefined z-coordinate to calculate a 3D viewpoint for viewing the 3Dobject 126, and updates the perspective of the 3D object 126 accordinglyduring movement. In FIG. 4A, the pointer 122 touches the 3D object 126on the 2D interactive surface 24, and drags it to the right. In FIG. 4B,the pointer 122 has completed dragging the 3D object 126 on the 2Dinteractive surface 24. The image of the 3D object 126 has been updatedsuch that its perspective has varied in accordance with respect to the3D viewpoint, as calculated based on the location of the camera icon128.

In this embodiment, a selection box is associated with each 3D object.The selection box appears as surrounding the associated 3D object whenthe 3D object is selected by a user, and disappears when the 3D objectis deselected or is manipulated in some prescribed manners, such as forexample, by rotating. FIG. 5 shows a selection box 162 associated with a3D object 160, as displayed on the 2D interactive surface 24. Theselection box 162 comprises several control regions that a user caninteract with to manipulate the 3D object 160. At least some of thecontrol regions are represented by control handle images. In the exampleshown in FIG. 5, these control regions are indicated by dashed lines.However, it will be understood that the dashed lines do not appear inthe actual user interface, and are shown for ease of reference only.

In this embodiment, each 3D object on the 2D interactive surface 24 hasa respective 3D object coordinate system associated therewith, with thex-y plane of the 3D object coordinate system being parallel to the 2Dinteractive surface 24 and with the z-axis being perpendicular to thex-y plane. FIG. 5 shows an example of the 3D object coordinate system140 associated with the 3D object 160. When a user rotates a 3D objectabout the x- or y-axis of the 3D object coordinate system, the directionof the z-axis of the 3D object coordinate system does not change, suchthat rotation of the 3D object about the z-axis always rotates the 3Dobject on a plane parallel to the 2D interactive surface 24. However,when a user rotates a 3D object about the z-axis, the x- and y-axes ofthe 3D object coordinate system, and the selection box, are rotatedtogether with the 3D object.

In the example shown in FIG. 5, the x-rotation zones 164 and 166 of theselection box 162, which are represented by respective control handles224 and 226 in the form of slider bars, allow a user to rotate the 3Dobject 160 about the x-axis (i.e., the rotation direction is on the y-zplane) by touching a pointer on the 2D interactive surface 24 within thex-rotation zone 164 or 166 and dragging the pointer along the y-axis.Those skilled in the art will appreciate that the pointer drag directiondoes not need to be precisely along the y-axis. Rather, components ofthe pointer dragging direction are projected by the interactive inputsystem 20 onto the x- and y-axes, and components projected onto thex-axis are disregarded. Moreover, when the 3D object 160 is rotatedabout the x-axis, the interactive input system 20 allows the pointer tobe dragged out of the x-rotation zones, while maintaining the x-rotationof the 3D object 160. The x-rotation is completed when the pointer islifted from the 2D interactive surface 24.

The y-rotation zones 168 and 170, which are represented by controlhandles 228 and 230, respectively, allow the user to rotate the 3Dobject 160 about the y-axis by applying a pointer on the 2D interactivesurface 24 within the y-rotation zone 168 or 170 and dragging thepointer along the x-axis, in a manner similar to the manipulation in thex-rotation zones 164 and 166 described above. The z-rotation zone 172represented by the z-rotation control handle 232 allows the user torotate the 3D object 160 about the z-axis. Control regions 174, 176, 178and 180 provide additional areas for rotation. Applying a pointer on the2D interactive surface 24 inside the region 174 or 176 and dragging thepointer to left or right rotates the 3D object 160 about the y-axis.Applying a pointer on the 2D interactive surface 24 inside the region178 or 180 and dragging the pointer up or down rotates the 3D object 160about the x-axis.

Other control regions are also defined in the selection box 162.Dragging the resizing control handle 182 scales the 3D object 160.Selecting contextual menu button 184 causes a contextual menu (notshown) related to the object 160 to pop-up and be displayed on the 2Dinteractive surface 24. The contextual menu includes menu items for,various functions, such as, for example, setting the 3D object back tothe default view, activating continuous spinning of the 3D object 160about a user-selected axis, starting or stopping continuous spinning,and applying different rendering styles such as wireframe mode or othermodes and enabling reflections. Dragging any of the corner areas 186,188, 190 and 192 between each neighbouring pair of control handles 164to 170 activates an arcball free rotation tool (not shown), which allowsthe user to freely rotate the 3D object in any direction in the 3Dobject coordinate system 140 about a rotation center, which in thisembodiment is the center of the selection box 162.

FIGS. 6A to 6C show resizing of the 3D object 160 using the resizingcontrol handle 182 of the selection box 162. In FIG. 6A, a pointer 122touches the resizing control handle 182 and drags it outwards by adesired amount, as indicated by the arrow 252. The selection box 162 andthe 3D object 160 are then enlarged to a size consistent with the amountof drag, as shown in FIG. 6B. Once the pointer releases the resizingcontrol handle 182 and touches a location outside of the selection box162, the selection box 162 disappears and the 3D object 160 remainsenlarged, as shown in FIG. 6C.

FIGS. 7A to 7D show rotation of the 3D object 160 about the z-axis usingthe z-rotation control handle 232 of the selection box 162. In FIG. 7A,the pointer 122 touches the z-rotation control handle 232 of theselection box 162. In response, the selection box 162 disappears, and acircular rotation indicator 256 encircling the 3D object 160 appears, asshown in FIG. 7B. A free rotation control element 258 also appears onthe circular rotation indicator 256 at a location corresponding to thetouch location of the pointer. The 3D object 160 is rotated by movingthe control element 258 around the circular rotation indicator 256.Dragging the control element 258 counter-clockwise with the pointer 122along the circular rotation indicator 256 causes the 3D object 160 torotate counter-clockwise, as shown in FIG. 7C. When the pointer 122 islifted from the 2D interactive surface 24, as shown in FIG. 7D, thecircular rotation indicator 256 disappears, the selection box 162reappears, and the 3D object 160 remains in the newly rotated position.

FIGS. 8A to 8D show rotation of the 3D object 160 about the y-axis usingthe control handle 228 of the selection box 162. In FIG. 8A, the 3Dobject 160 has been selected and the selection box 162 has appearedaround the 3D object 160. When the pointer 122 touches the controlhandle 228 and slides it horizontally to the right, as shown in FIG. 8B,the control handle 228 remains visible to provide a rotation indicator,and other portions of the selection box 162 disappear. This providesfeedback to the user that rotation is restricted to about the y-axis.When the pointer 122 slides to the right on the control handle 228, the3D object 160 is rotated proportionally about the y-axis, as shown inFIG. 8C. A color variation (not shown) on the control handle 228provides feedback to the user as to the amount of rotation of the 3Dobject 160. When the pointer 122 is lifted from the 2D interactivesurface 24, the rotation indicator, namely the colored control handle228, disappears and the selection box 162, including the control handle228 without color variation, re-appears around the 3D object 160, asshown in FIG. 8D. The 3D object 160 remains in the newly rotatedposition.

FIGS. 9A to 9D show rotation of the 3D object 160 about the x-axis usingthe control handle 224 of the selection box 162. In FIG. 9A, the 3Dobject 162 has been selected and the selection box 162 has appearedaround the 3D object 160. When the pointer 122 touches the controlhandle 224 and slides vertically downwards, as shown in FIG. 9B, thecontrol handle 224 remains as a rotation indicator, and other portionsof the selection box 162 disappear. This provides feedback to the userthat the rotation is restricted to about the x-axis. When the pointer122 is slid downwardly, the 3D object 160 is rotated proportionallyabout the x-axis, as shown in FIG. 9C. A color variation (not shown) onthe control handle 224 provides feedback to the user as to the amount ofrotation of the 3D object 160. When the pointer 122 is lifted from the2D interactive surface 24, the rotation indicator, namely the coloredcontrol handle 224, disappears and the selection box 162, including thecontrol handle 224 without color variation, re-appears around the 3Dobject 160, as shown in FIG. 9D. The 3D object 160 remains in the newlyrotated position.

FIGS. 10A to 10D show rotation of the 3D object 160 in the 3D spaceusing an arcball free rotation tool of the selection box 162. When anarea 190 between control handles 226 and 228 of the selection box 162 istouched by the pointer 122, as shown in FIG. 10A, the selection box 162disappears and a rotation indicator comprising an arcball free rotationtool 262 appears, as shown in FIG. 10B. The arcball free rotation tool262 is positioned at a corner of the selection box 162 nearest to thetouch point and a boundary box 266, which appears surrounding the 3Dobject 160. The arcball free rotation tool 262 comprises a grid pattern264 to provide the user with feedback indicating the amount of rotation.The arcball free rotation tool 262 is operated by touching the pointer122 on the 2D interactive surface 24 at a position within the arcballfree rotation tool 262, and then moving the pointer 122 on the 2Dinteractive surface 24. When movement of the pointer 122 is detected,the movement is interpreted as rotation of the arcball free rotationtool 262 and the 3D object 160 is rotated in the direction of themovement of the pointer 122, as shown in FIG. 10C. When the pointer 122is lifted from the 2D interactive surface 24, either for greater than apredetermined period of time or immediately when the pointer 122 touchesanother location on the 2D interactive surface 24, the boundary box 266disappears and the selection box 162 reappears around the 3D object 160.The 3D object 160 remains in the newly rotated position (not shown). Aswill be understood, the arcball free rotation tool 262 allows the 3Dobject 160 to be freely rotated in any direction in 3D space.

In this embodiment, the arcball free rotation tool 262 also provides asnap-to-axis function. A horizontal region 268 and a vertical region 270are defined as snap-to-axis zones, as shown in FIG. 10D. If the pointer122 is moved to within the horizontal region 268 while the arcball freerotation tool 262 is being rotated, the rotations of the arcball freerotation tool 262 and of the 3D object 160 are restricted to rotationabout the y-axis. Similarly, if the pointer 122 is moved to within thevertical region 270 while the arcball free rotation tool 262 is beingrotated, the rotations of the arcball free rotation tool 262 and of the3D object 160 are restricted to rotation about the x-axis. In thisembodiment, when the pointer 122 moves into one of the regions 268 or270 while the arcball free rotation tool 262 is being rotated, therespective snap-to-axis region is highlighted, such as for example byfilling with a semi-transparent color, indicating that the rotation isnow restricted to about the x-axis or the y-axis. When the pointer movesout of the region, the highlighting of the snap-to-axis regiondisappears, and the arcball free rotation tool 262 and the 3D object 160are again freely rotated according to the movement of the pointer 122.

FIGS. 11A to 11E show a flowchart of the steps of a 3D objectmanipulation method used by the interactive input system 20. The 3Dobject manipulation method is carried out by computing device 28 forrotating or moving the 3D object on the 2D interactive surface 24 basedon pointer events received by the computing device 28 from theinteractive board 22. As will be understood, a pointer event may be anyof a pointer-down event that occurs when a pointer is brought intocontact on the 2D interactive surface 24, a pointer-move event thatoccurs when the pointer is moved from one location to another on the 2Dinteractive surface 24 while maintaining continuous contact with the 2Dinteractive surface 24, and a pointer-up event that occurs when thepointer is lifted from the 2D interactive surface 24.

Turning to FIG. 11A, when the computing device 28 receives a pointerevent (step 280), the computing device 28 determines if the receivedpointer event is a pointer-down event occurring at a position on the 2Dinteractive surface 24 within the 3D object (step 282), signifying thatthe 3D object has been touched by a user. If the pointer event is not apointer-down event, then the method proceeds to step 280 to await thenext pointer event. If, at step 282, the pointer event is a pointer-downevent, then computing device 28 waits to receive the next pointer event(step 284). When the next pointer event is received, the computingdevice 28 checks to determine if the next pointer event is apointer-move event (step 286). If the next pointer event is apointer-move event, the computing device 28 translates the location ofthe 3D object to the location of the pointer, namely the location atwhich the pointer-move event has occurred (step 288). The computingdevice 28 then waits to receive the next pointer event (step 290). Afterthe next pointer event is received, the computing device 28 checks todetermine if the next pointer event is a pointer-up event (step 292). Ifnext the pointer event is not a pointer-up event, such as for example ifthe next pointer event is a pointer-move event, the method proceeds tostep 288 to translate the location of the 3D object to the location ofthe pointer. If, at step 292, the pointer event is a pointer-up event,then the method proceeds to step 280 to receive the next pointer event.

If, at step 286, the pointer event is not a pointer-move event, meaningthat the pointer event is a pointer-up event, then the computing device28 displays the selection box 162 enclosing the 3D object and hides therotation indicator, including any boundary box 266 and any arcball freerotation tool 262, if the rotation indicator is currently shown (step294). The computing device 28 then waits to receive the next pointerevent (step 296), which will be a pointer-down event. When the nextpointer event is received, the computing device 28 determines thelocation of the pointer-down event (step 298).

If at step 298 the pointer-down event occurs outside the selection box162 surrounding the 3D object, the computing device 28 hides theselection box 162 (step 300), and the method proceeds to step 280 toreceive the next pointer event. If at step 298, the pointer-down eventoccurs on a corner region 186, 188, 190 or 192 between adjacent slidersof the selection box 162, the computing device 28 shows the rotationindicator, including the boundary box 266 and the arcball free rotationtool 262, at the corner of the selection box nearest to the pointerevent location, and hides the selection box 162 (step 302). Then, themethod then proceeds to step 330, shown in FIG. 11B, as illustrated byconnector A.

Turning now to FIG. 11B, at step 330, the computing device 28 checks todetermine if the location of the pointer event is in a snap-to-axiszone. If the location of the pointer event is in a snap-to-axis zone,the computing device 28 rotates the 3D object only about thecorresponding axis (step 334), and the method proceeds to step 336. Forexample, if the location of the pointer event is in the horizontalsnap-to-axis zone 268, as shown in FIG. 10D, then the 3D object isrotated about the y-axis only. If the location of the pointer event isin the horizontal snap-to-axis zone 270, then the 3D object is rotatedabout the x-axis only.

Turning again to FIG. 11B, if at step 330, the location of the pointerevent is not in a snap-to-axis zone, the computing device 28 rotates the3D object in the direction of the pointer movement (step 332) and themethod proceeds to step 336. At step 336, the computing device 28receives the next pointer event. The computing device 28 then checks todetermine if the pointer event is a pointer-move event (step 338). Ifthe pointer event is a pointer-move event, the method proceeds to step330. If the pointer event is not a pointer-move event, meaning that thepointer event is a pointer-up event, then the computing device 28 startsa timer (step 340), and checks to determine if the next pointer event isreceived (step 342). If no pointer event is received, the computingdevice 28 then checks the timer to determine if a threshold period oftime from the previous pointer event has passed (step 344). If thethreshold time period has not passed, the method returns to step 342. Ifthe threshold time period has passed, then the computing device 28 stopsthe timer (step 348), and the method returns to step 294 in FIG. 11A, asillustrated by connector F.

If at step 342, a pointer event, which will be a pointer-down event, isreceived, then the computing device 28 stops the timer (step 346), andthe method returns to step 296 in FIG. 11A, as illustrated by connectorE.

Turning again to FIG. 11A, if at step 298, the arcball free rotationtool 262 is shown and the pointer-down event occurs on the arcball freerotation tool, the method proceeds to step 330 in FIG. 11B, illustratedby connector A.

If at step 298, the pointer-down event occurs on the z-rotation controlhandle 232, then the method proceeds to step 352 in FIG. 11C,illustrated by connector B. At step 352, the computing device 28 hidesthe selection box 162 and the rotation indicator, if they are currentlyshown, and displays the circular rotation indicator 256 around the 3Dobject as well as the free rotation control element 258 (step 352). Atstep 354, the computing device 28 rotates the 3D object about the z-axisbased on user movement of the control element 258 around the circularrotation indicator 256. The computing device 28 then waits to receivethe next pointer event (step 356). After the next pointer event isreceived, the computing device 28 checks to determine whether thepointer event is a pointer-move event (step 358). If the pointer eventis a pointer-move event, the method proceeds to step 354 to rotate the3D object; otherwise, the method returns to step 294 in FIG. 11A, asillustrated by connector F.

Turning once again to FIG. 11A, if at step 298, the location of thepointer-down event is on the 3D object, the method proceeds to step 372in FIG. 11D, as illustrated by connector C. Referring to FIG. 11D, atstep 372 the computing device 28 hides the selection box 162 androtation indicator, if they are currently shown (step 372), andtranslates the 3D object to the current pointer location on the 2Dinteractive surface 24 (step 374). The computing device 28 then waits toreceive the next pointer event (step 376). After the next pointer eventis received, the computing device 28 checks to determine whether thepointer event is a pointer-move event (step 378). If the pointer eventis a pointer-move event, the method returns to step 374 to update thelocation of the 3D object; otherwise, the method returns to step 294 inFIG. 11A, as illustrated by connector F.

Referring to FIG. 11A, at step 298, if the location of the pointer-downevent is on a slider bar of the selection box 162, the method proceedsto step 392 in FIG. 11E, as illustrated by connector D. Referring toFIG. 11E, at step 392, the computing device 28 hides the selection box162 and the rotation indicator, if they are currently shown, and showsthe slider coinciding with the location of the pointer event (step 392).The computing device 28 then determines the rotation of the 3D objectbased on which slider is being contacted by the pointer (step 394). Ifthe pointer is touching a vertical slider, namely control handle 224 or226, then the computing device 28 rotates the 3D object about the x-axis(step 396). The computing device 28 then waits to receive the nextpointer event (step 398). After the next pointer event is received, thecomputing device 28 checks to determine whether the pointer event is apointer-move event (step 400). If the pointer event is a pointer-moveevent, the method returns to step 396; otherwise, the method proceeds tostep 294 in FIG. 11A, as illustrated by connector F.

If at step 394, the pointer is touching a horizontal slider, namelycontrol handle 228 or 230, then the computing device 28 rotates the 3Dobject about the y-axis (step 402). The computing device 28 then waitsto receive the next pointer event (step 404). After the next pointerevent is received, the computing device 28 checks to determine whetherthe pointer event is a pointer-move event (step 406). If the pointerevent is a pointer-move event, the method returns to step 402;otherwise, the method proceeds to step 294 in FIG. 11A.

FIGS. 12A to 12C show an alternative selection box for manipulating 3Dobjects on the 2D interactive surface 24, and which is generallyindicated using reference numeral 410. In FIG. 12A, the selection box410 is shown enclosing a selected 3D object 160. In this embodiment, theselection box 410 comprises a vertical scroll bar 412 and a horizontalscroll bar 414 having operable control elements. In the embodimentshown, the operable control elements are movable cursors 416 and 418,respectively. The scroll bar 412 provides a resizing function, such thatmoving cursor 416 upwards as shown in FIG. 12B enlarges the size of the3D object 160 while moving cursor 416 downwards reduces the size of the3D object 160. The scroll bar 414 provides a rotation function to rotatethe 3D object 160 about the y-axis such that moving cursor 418 to theright rotates the 3D object 160 to the right about the y-axis, as shownin FIG. 12C, while moving cursor 418 to the left rotates the 3D object160 to the left about the y-axis.

Those skilled in the art will understand that, in other embodiments,other functionalities may alternatively be applied to one or more of thecontrol handles, and that the selection box may alternatively comprisemore or fewer control handles.

Although in embodiments described above, the arcball free rotation toolcomprises a snap-to-axis function, in other embodiments, the arcballfree rotation tool may alternatively not provide a snap-to-axisfunction.

Those skilled in the art will understand that, in other embodiments, theboundary box surrounding the 3D object may alternatively not appear whenthe arcball free rotation tool is activated.

Although in embodiments described above, the rotation indicatordisappears immediately after the pointer is lifted from the x-, y- orz-rotation zone, in other embodiments, the rotation indicator mayalternatively disappear only after the pointer is lifted from the x-, y-or z-rotation zone for a threshold period of time, or immediately afterthe pointer touches the 2D interactive surface at a position outside therespective zone.

Although in embodiments described above, the rotation indicatorcomprising an arcball free rotation tool appears when an area betweencontrol handles of the selection box is touched by the pointer, in otherembodiments, alternatives are possible. For example, in otherembodiments, after a 3D object is selected, the arcball free rotationtool may alternatively be activated when either the 3D object or acorner between adjacent sliders is touched by the pointer. In otherembodiments, the arcball free rotation tool may alternatively beactivated when a 3D object is selected. In still other embodiments, the3D object may alternatively be freely rotated without showing the arcball free rotation tool when the 3D object is touched after theselection box is displayed.

Those skilled in the art will understand that the appearances of theselection boxes and the rotation indicators described above areexemplary only, and that in other embodiments, the selection boxes andthe rotation indicators may alternatively be represented by differentgraphics providing the same or similar functionalities. For example, inone embodiment, when a 3D object is selected, small circles appear inthe control regions of the selection box to indicate to the user theexistence of the control regions for manipulating the 3D object.

Those skilled in the art will also appreciate that, in otherembodiments, the rotation indicator may alternatively not be displayedwhen the user is rotating a 3D object.

Although in embodiments described above, each 3D object on the 2Dinteractive surface has a respective 3D object coordinate systemassociated therewith, in other embodiments, all 3D objects on the 2Dinteractive surface share the same 3D object coordinate system, forwhich the x-y plane is parallel to the 2D interactive surface and thez-axis is perpendicular to the x-y plane. In this embodiment, rotating a3D object around any of the x-, y- or z-axis does not change thedirection of other axes.

Although in embodiments described above, each digital tool that is notassociated with digital content has a respective representative imagethat is displayed on the 2D interactive surface, in other embodiments, adigital tool that is not associated with digital content mayalternatively have no respective representative image displayed on the2D interactive surface.

Although in embodiments described above, the selection tool is a digitalcontent manipulation tool for selecting digital content, in otherembodiments, the selection tool may itself be treated as a digitalcontent object.

Although in embodiments described above, a color variation on thecontrol handle provides feedback to the user as to the amount ofrotation of the 3D object, in other embodiments, other indicators mayalternatively be used with the slider bar to provide feedback to theuser as to the amount of rotation of the 3D object, such as for example,a number indicating a rotation angle. In other embodiments, no feedbackis alternatively provided as to the amount of rotation of the 3D object.

Now, turning to FIGS. 13A and 13B, another alternative selection box formanipulating a 3D object on the 2D interactive surface 24 is shown andis generally indicated by reference numeral 500. Selection box 500surrounds a 3D object (not shown) and comprises a plurality of controlregions, namely a z-rotation region 502, an x-rotation region 504, and ay-rotation region 506, all of which may be used to rotate the 3D objectabout its z-, x- and y-axes, respectively. Selection box 500 furthercomprises a free rotation region 508, and a position translation region510 that may be used to move the 3D object to another location on the 2Dinteractive surface 24. Each of the rotation regions 502 to 508 has arespective visual indicator that is displayed upon selection of the 3Dobject. For example, FIG. 13B shows a visual indicator in the form of anarcball associated with the free rotation region 508.

Still other alternative selection boxes for manipulating a 3D object onthe 2D interactive surface 24 are possible. For example, FIG. 14A showsan unselected 3D object 540 displayed on the 2D interactive surface 24.As the 3D object 540 has not been selected, no selection box surroundsthe 3D object 540. After the 3D object 540 is selected by touching witha pointer, a selection box 542 appears surrounding the 3D object 540, asshown in FIG. 14B. The selection box 542 comprises a z-rotation controlhandle 544, an x-rotation control handle 546, which in this example isan arc with an arrow at each end defining an x-rotation region, ay-rotation control handle 548, which in this example is an arc with anarrow at each end defining a y-rotation region, and a free rotationcontrol handle 550 indicating a free rotation region. The selection box542 also comprises a context menu button 552 and a resizing controlhandle 554. In this embodiment, the x- and y-rotation control handles546 and 548 begin to fade out (not shown) if the selected 3D object 540is not touched for a threshold first time period, and completelydisappear, as shown in FIG. 14C, after the selected 3D object 540 hasnot been touched for a threshold second time period. Touching the 3Dobject 540 again to causes the x- and y-rotation control handles 546 and548 to re-appear.

The rotation control handles 544 to 550 are used to rotate the 3D object540. For example, touching and dragging the z-rotation control handle544 rotates the 3D object 540 about the z-axis. During such rotation ofthe 3D object 540, the selection box 542 disappears and a rotationindicator 560 appears, as shown in FIG. 14D. The rotation indicator 560comprises a circle 562, a rotation starting point indicator 564, acurrent rotation position indicator 566, an arrow 568 indicating thedirection of rotation, and text 570 showing the angle of rotation.

The x-rotation control handle 546 may be touched and dragged to rotatethe 3D object 540 about the x-axis. During such rotation, the selectionbox 542 disappears and a rotation indicator 580 appears, as shown inFIG. 14E. The rotation indicator 580 comprises an elliptic circle 582, arotation starting point indicator 584, a current rotation positionindicator 586, an arrow 588 indicating the direction of rotation, andtext 590 showing the angle of rotation.

Similarly, the y-rotation control handle 548 may be touched and draggedto rotate the 3D object 540 about the y-axis. During such rotation, theselection box 542 disappears and a rotation indicator 620 appears, asshown in FIG. 14F. The rotation indicator comprises an elliptic circle622, a rotation starting point indicator 624, a current rotationposition indicator 626, an arrow 628 indicating the direction ofrotation, and text 630 showing the angle of rotation.

FIGS. 15A to 15D show still another alternative selection box formanipulating a 3D object on the 2D interactive surface 24, and which isgenerally indicated by reference numeral 800. Selection box 800comprises a resizing control handle 801 for manipulating the size of the3D object 160, rotation control handles 802, 804, 806 and 808, and acontext menu button 809. In this embodiment, the rotation controlhandles 802, 804, 806 and 808 are displayed as full visualizationimages, and are configured to permit manipulation of the 3D object 160,when the size of the 3D object 160 is greater than a threshold size,based on pixel size. As will be understood by those skilled in the art,the threshold size may be chosen so as to prevent rotation controlhandles from overlapping. When the size of the 3D object is smaller thanthe threshold size, the rotation control handles 802, 804, 806 and 808are displayed as compact visualization images, and their manipulationfunctionalities are disabled. In this embodiment, the full visualizationimages of rotation control handles 802, 806 and 808 are arcs each witharrows on both ends, and the compact visualization images thereof aredots. The full and compact visualization images of the rotation controlhandle 804 are arc balls of large and small sizes, respectively.

Each of the rotation control handles 802, 804, 806 and 808 has arespective function. In the embodiment shown, the z-rotation controlhandle 802 is configured for rotating the 3D object 160 about thez-axis, the x-rotation control handle 806 is configured for rotating the3D object 160 about the x-axis, the y-rotation control handle 808 isconfigured for rotating the 3D object 160 about the y-axis, and the freerotation control handle 804 is configured for freely rotating the 3Dobject 160 in any direction.

The resizing control handle 801 may be used to change the size of the 3Dobject 160, as shown in FIG. 15A. Moving the resizing control handle 801inwardly reduces the size of the 3D object 160, while moving theresizing control handle 801 outwardly increases the size of the 3Dobject 160.

In FIG. 15B, both the selection box 800 and 3D object 160 have beendecreased in size as a result of a user selecting and dragging theresizing control handle 801 inwardly, and in a direction indicated byarrow 814. This resizing has decreased the size of the 3D object 160 tobelow the threshold size, which in turn has caused the rotation controlhandles 802, 804, 806 and 808 to transition from full visualizationimages to compact visualization images, shown as dots 810A, 810B and810C and mini-arcball 810D, at locations previously occupied by the fullvisualization images 802, 806, 808 and 804, respectively. In thisembodiment, this transition is smooth, such that the full visualizationimages fade out and the compact visualization images fade in.

In FIG. 15C, a 3D object 812 has been selected by a user, and theselection box 800 has appeared surrounding the 3D object 812. As thesize of the 3D object 812 is smaller than the threshold size, the z-,x-, y- and free rotation control handles are shown as dots 810A, 810B,810C and 810D, respectively. When the resizing control handle 801 isdragged outwardly by a pointer 122, in a direction indicated by arrow816, and the size of the 3D object is increased to above the thresholdsize, the compact visualization images of rotation control handles,namely dots 810A, 810B and 810C and mini-arcball 804D, transition tofull visualization images 802, 806, 808 and 804, as shown in FIG. 15D.In this embodiment, this transition is smooth, such that the compactvisualization images fade out as the full visualization images fade in.The 3D object 812 may now be rotated about the z-, x- or y-axis or inany direction using the pointer 122, for example.

FIG. 16 is a flowchart showing the steps performed during a 3D objectmanipulation method using the selection box 800, and which is generallyindicated using reference numeral 818. Those skilled in the art willunderstand that the method 818 is not limited to manipulation of 3Dobjects only, and may also be applied to manipulation of other forms ofdigital content.

When a pointer contacts the 2D interactive surface 24, the computingdevice 28 receives the resulting touch input event from the interactiveboard 22 (step 820), and determines if the touch input event correspondsto selection or resizing of a 3D object (step 822). If the touch inputevent does not correspond to selection or resizing of a 3D object, thecomputing device 28 then checks if the touch input event corresponds tode-selection of a 3D object (step 824). If the received touch inputevent corresponds to de-selection of a 3D object, then the selection boxaround the 3D object is removed from display (step 828), and the methodreturns to step 820. If the received touch input event does notcorrespond to de-selection of an object, then the computing device 28processes the touch input event based on the specifics thereof (step832), and the method returns to step 820.

If, at step 822, the touch input event corresponds to selection orresizing of a 3D object, the selection box 800 is displayed around thegraphic object (step 826). The 3D object is thus selected. Then, thecomputing device 28 checks to determine if the size of the 3D object islarger than the threshold size (step 830). If the size of the 3D objectis above the threshold size, full visualization images of the rotationcontrol handles are displayed (step 834). The rotation control handlesare also enabled to allow manipulation of the 3D object (step 838). Thecomputing device 28 then checks if the rotation control handles werepreviously represented by the compact visualization images (step 842),and, if so, hides the compact visualization images (step 846). Themethod then returns to step 820.

If, at step 830, the size of the 3D object is below the threshold size,compact visualization images of the rotation control handles are thendisplayed (step 836), and the rotation control handles are disabled(step 840). The rotation control handles are therefore no longeravailable to rotate the 3D object. The computing device 28 then checksto determine if the rotation control handles were previously representedby the full visualization images (step 842), and, if so, hides the fullvisualization images (step 846). The method then returns to step 820.

It will be understood that, in the above method, removal of any imagefrom display may comprise either hiding the image, namely removing theimage from display but still storing the image in memory, or deletingthe image, namely removing the image from display and from memory.

In this embodiment, the threshold size is a predefined value equal totwo (2) times the largest value of the lengths and widths of the fullvisualization images of rotation control handles 802, 806 and 808, andmeasured in units of display pixels. If, at step 830, any one of thelength and width of the selected 3D object is larger than the thresholdsize, then the method branches to step 834 to display the fullvisualization images of the rotation control handles; otherwise, themethod branches to step 836 to display the compact visualization imagesof the rotation control handles.

Those skilled in the art will appreciate that in other embodiments,other threshold sizes may alternatively be used. For example, thethreshold size may alternatively be measured in other units such as forexample inches, millimeters, and the like. In still other embodiments,the size comparison criteria used may alternatively be a comparison ofthe diagonal length of the selected 3D object with a threshold size,which may be a predefined value or a value defined based on the diagonallength of the full visualization images of rotation control handles. Infurther embodiments, the diagonal length of the 3D object or of thevisualization images may be defined as the diameter of a bounding circleenclosing the 3D object or visualization images, respectively. In otherembodiments, the diagonal length of the 3D object or visualizationimages may alternatively be defined as the diagonal length of a boundingrectangle enclosing the 3D object or the visualization images,respectively. In other embodiments, an aspect ratio of the selected 3Dobject and/or the full/compact visualization images of rotation controlhandles is also considered in with the size comparison criteria.

In still other embodiments, the size comparison criteria mayalternatively comprise a comparison of the area of the selected 3Dobject and a predefined threshold area size. In still other embodiments,the size comparison criteria may alternatively be based on the shape ofthe 3D object, and the threshold area size may alternatively bedynamically calculated so that the full visualization images of rotationcontrol handles are displayed only until they start to overlap.

In the embodiments described above, users are not able to change thethreshold size and the size comparison criteria, however, in otherembodiments, users may alternatively be provided with an option forallowing the user to customize any of the threshold size, the thresholdarea size and the comparison criteria.

Although in the embodiments described above, the free rotation controlhandle is not considered in the size comparison, in other embodiments,the free rotation control handle may alternatively be also considered insize comparison.

To help the user differentiate the functionality of each rotationcontrol handle, in some embodiments, each of the rotation controlhandles, whether displayed as full or as compact visualization images,may have any of a unique color, a unique shape, a unique shade, or otherunique visual characteristic associated therewith. For example,referring to FIG. 15A, the rotation control handles 802, 806, 808 may becolored red, green and blue, respectively, in such other embodiments.Similarly, referring to FIG. 15B, dots 810A, 810B and 810C may becolored red, green and blue, respectively, in such other embodiments. Itwill be understood that other colors may alternatively be used. Theopacity or the transparency of the rotation control handles 802, 804,806 and 808 may also vary, and may range from fully visible to fullyhidden.

Although in the embodiments described above, all of the rotation controlhandles transition between full and compact visualization imagessynchronously, in other embodiments, all of the rotation control handlesmay alternatively transition between full and compact visualizationimages asynchronously. For example, the x-rotation and y-rotationcontrol handles may each transition to a respective compactvisualization image at different times.

Although in the embodiments described above, the rotation controlhandles are disabled when they are displayed as compact visualizationimages, in other embodiments, the rotation control handles mayalternatively not be disabled when they are displayed as compactvisualization images, so that a user is still able to rotate the 3Dobject using the rotation control handles. In still other embodiments,the rotation control handles are hidden and are disabled when the sizeof the 3D object is below the threshold size.

In other embodiments, a second threshold size may also be used, suchthat the rotation control handles disappear when the 3D object isresized to a size below the second threshold size. In a relatedembodiment, the rotation control handles may alternatively be enabledwhen they are displayed as full visualization images when the size ofthe 3D object is larger than the first threshold size, or as compactvisualization images when the size of the 3D object is smaller than thefirst threshold size but is larger than the second threshold size.However, the rotation control handles are hidden and are disabled whenthe size of the 3D object is smaller than the second threshold size. Inanother related embodiment, when the size of the 3D object is smallerthan the first threshold size but is larger than the second thresholdsize, the x-, y- and z-rotation control handles are enabled and aredisplayed as compact visualization images, but the free rotation controlhandle is disabled and/or hidden.

In still other embodiments, the rotation control handles mayalternatively never be disabled, such that the selected 3D object may berotated whether the rotation control handles are displayed as full or ascompact visualization images, or when no rotation control handles aredisplayed.

Turning now to FIG. 17, a flowchart showing the steps of a method forlabelling and annotating a 3D object is shown, and is generallyindicated by reference numeral 850. To label and annotate a 3D object,the user first selects a label tool (step 852), which may be done byselecting a label tool icon in a toolbar. The user then places an anchorpoint on the 3D object (step 854), by, for example, bringing a pointerinto contact with the 2D interactive surface 24 at a desired location onthe 3D object. When the pointer is lifted from the 2D interactivesurface 24, a label box is anchored to the 3D graphic object at thepointer contact location (step 856). It will be understood that steps852 to 856 may be repeated as desired to anchor multiple label boxes tothe 3D object.

After the user finishes anchoring label boxes to the 3D object, the usermay annotate text on an anchored label box using one of a cursor tooland a pen tool. To annotate text, the user selects a desired tool (step856). If the cursor tool is selected (step 862), the user selects alabel box, such as by touching the box with the pointer, and inputs textthereto using a keyboard (step 866). If the pen tool is selected (step860), the user applies digital ink annotation to a desired label box bywriting thereon using the pointer (step 864). The user may also applydigital ink annotation at any location of the 2D interactive surface 24,and then drag the digital ink annotation into a label box as desired. Itwill be understood that steps 858 to 866 may also be repeated as desiredto add annotations to multiple anchored label boxes.

The anchor points and/or label boxes may be displayed in differentmanners (e.g., in different shapes, sizes, colors, animations,backgrounds, borders, etc.) in different embodiments, eitherautomatically or as user designated. A label box can be collapsed intoits corresponding anchor point by tapping on the anchor point or labelbox after the anchored label box has been created. When a label box iscollapsed, a user can tap on the anchor point to expand the label box,causing it to be displayed. The user may also deselect a 3D object, asdescribed above. When a 3D object is deselected, the label boxesanchored thereto are still shown. However, those skilled in the art willappreciate that, in an alternative embodiment, label boxes anchored to a3D object may be hidden when the 3D object is not selected.

In this embodiment, the label boxes anchored to a 3D objectautomatically collapse or expand, depending on the size of the 3Dobject. FIGS. 18A and 18B illustrate an example of automatic collapse orexpansion of label boxes anchored to a 3D object based on the size ofthe 3D object. The size of the 3D object may be changed throughinteraction with the 2D interactive surface 24, such as for example bydragging a resizing control handle, or by changing the position of amarker within the 3D input space 60. In the example shown in FIGS. 18Aand 18B, a user has placed a selection tool marker 868 within the 3Dinput space 60, and has selected a 3D object 160 having three labelboxes 872A, 872B and 872C anchored thereto at anchor points 870A, 870Band 870C, respectively.

In FIG. 18A, the user has moved the marker 868 to a location in the 3Dinput space 60 distant from the camera 54, so that the size of the 3Dobject 160 is smaller than a predefined display threshold. As a result,the anchor points 870A to 870C are displayed on the 3D object 160, butthe label boxes 872A to 872C are automatically collapsed and are notshown. The display threshold may be defined in several ways, similar tothe definition of the threshold size described above. For example, inthis embodiment, the display threshold is defined based on the displaysize (in pixels) for which the letters in label boxes aredistinguishable to users.

In FIG. 18B, the user has moved the marker 868 in the 3D input space 60closer to the camera 54, so that the size of the 3D object 160 hasbecome larger than the predefined display threshold. Consequently, labelboxes 872A to 872C are automatically expanded, and are displayed on the2D interactive surface 24. Each label box 872A to 872C is visuallylinked to its corresponding anchor point 870A to 870C by a straightline. In this example, when the 3D object 160 is enlarged, the anchorpoints are also enlarged, however it will be understood that in otherembodiments, the size of the anchor points may alternatively not scalewith the size of the 3D object.

FIG. 19 is a flowchart showing the steps of a method for displayinglabel boxes on a 3D object, and which is generally referred to usingreference numeral 874. For ease of description, it is assumed that a 3Dobject annotated with label boxes is associated with a marker in the 3Dinput space 60. The computing device 28 first tracks the marker, andcalculates the size of the 3D object (step 876). The computing device 28then checks if the size of the 3D object is larger than the displaythreshold (step 878). If the size of the 3D object is not larger thanthe display threshold, the computing device 28 modifies the imagedisplayed on the 2D interactive surface 24 so as to hide the labelboxes, if they are not already hidden (step 880), and disables textmanipulation of label boxes (step 884). In this embodiment, the anchorpoints are always displayed regardless of whether the label boxes arehidden or not hidden.

If, at step 878, the size of the 3D object is larger than the displaythreshold, then the computing device 28 modifies the image displayed onthe 2D interactive surface 24 to display the label boxes, if they arenot already displayed (step 882), and enables text manipulation of thelabel boxes (step 886). The computing device 28 then checks to determineif the marker has been removed from the 3D input space 60, meaning thatit would not be detectable in images captured by the camera 54 (step888). If the marker has not been removed from the 3D input space 60, andis therefore still in the 3D input space 60, then the method returns tostep 878; otherwise, the method ends.

It will be understood that any of the label boxes and the anchor pointsmay have similar appearances and behaviour characteristics as therotation control handles in embodiments described above. For example, inother embodiments, the anchor points may alternatively be hidden whenthe size of the 3D object is smaller than a second display threshold.

It will also be understood that different opacity levels can be appliedto the label boxes, based on the z-depth of the anchor point, namely theposition of the anchor point along z-axis, so as to allow a user to moreeasily focus on a point of interest. For example, in other embodiments,label boxes linked to the anchor points that are “higher” along z-axismay become more transparent while label boxes linked to the anchorpoints that are “lower” along z-axis may become more opaque.

Although in embodiments described above, a marker is used to manipulatethe 3D object, in other embodiments, the user may also manipulate the 3Dobject by interacting with the 2D interactive surface. In such otherembodiments, the label boxes automatically collapse or expand when thesize of the 3D object becomes larger or smaller, respectively, than athreshold size. In a related embodiment, the user may alternativelymanipulate 3D object by interacting with the 2D interactive surface asdescribed above, regardless of whether the MR mode is turned on or not.

In still other embodiments, the interactive input system mayalternatively not comprise any 3D input device. In these otherembodiments, a user may manipulate 3D objects by interacting with the 2Dinteractive surface as described above, or by using other input devices,such as, for example, any of the mouse and the keyboard.

In still other embodiments, the interactive input system mayalternatively not comprise an interactive board. In these otherembodiments, a user may manipulate 3D objects by manipulation of markersin the 3D input space, or by using other input devices, such as, forexample, any of the mouse and the keyboard.

In still other embodiments, the images output from the computing devicemay alternatively be displayed on a display surface separate from the 2Dinteractive surface.

In still other embodiments, when a 3D object is touched, the selectionbox may alternatively not be automatically be displayed.

In still other embodiments, multiple pointer touches may alternativelybe used to rotate 3D objects by fixed amounts. For example, placement oftwo pointers on a horizontal slider control handle of the selection box,and located to the right of the center of the control handle, mayalternatively cause a 15 degree rotation of the 3D object about they-axis. Similarly, placement of three pointers on the control handle,and located to the right of the center of the control handle, mayalternatively cause a 60 degree rotation. Placement of a first pointeron the z-rotation control handle and a second pointer slightly to theright of the z-rotation control handle, may alternative cause a discreterotation of the 3D object clockwise about the z-axis, while placement ofa first pointer on the z-rotation control handle and a second pointerslightly to the left of the z-rotation control handle may alternativelycause a discrete rotation of the 3D object counter-clockwise about thez-axis.

In still other embodiments, animation of 3D objects, such as spinanimations, can be caused by gestures detected within the selection box.In one such other embodiment, a “flick” gesture, which is a drag gesturehaving a speed above a drag speed threshold, can be used to operate anyof the slider control handles and the rotation control handles. In thisother embodiment, a left-to-right flick gesture on the horizontal slidercontrol handle causes the 3D object to spin from left to rightcontinuously about the y-axis, while a right-to-left flick on thehorizontal slider causes 3D object to spin from right to leftcontinuously about the y-axis. Similarly, a down-to-up flick gesturecauses the 3D object to spin upwards continuously about the x-axis,while an up-to-down flick causes the 3D object to spin downwardscontinuously about the x-axis. In this same other embodiment, a flickgesture on the z-rotation control handle causes the 3D object to spinclockwise or counter-clockwise continuously about the z-axis, dependingon the direction of the flick gesture. In these other embodiments, whena spin animation begins, the selection box disappears. Touching the 3Dobject with a pointer stops the spin animation and causes the selectionbox to reappear.

In other embodiments, the computing device may alternatively determinethat manipulation of a 3D object has been completed according to any ofthe following: when another 3D object is selected; after expiration of athreshold time of inactivity; immediately after the pointer no longertouches the control handle used to manipulate the 3D object; and whenthe user steps outside a predefined proximity of the 2D interactivesurface.

Although in embodiments described above, the control handle is used toenlarge the size of a selection box and a 3D object, whereby the controlhandle is dragged by a desired amount and the selection box and the 3Dobject are then enlarged according to a size consistent with the amountof drag, in other embodiments, the control handle may alternatively beused to change the z-position of the 3D object in the 3D space “above”the 2D interactive surface, namely the position of the 3D object alongthe z-axis. In this other embodiment, when the control handle is draggedby a desired amount, the z-position of the 3D object in the 3D space isrecalculated, and the 3D object is resized according to the change ofthe z-position. For example, when the control handle is draggedoutwards, the 3D object is moved towards the user in 3D space, namelythe 3D object is moved further above the 2D interactive surface, therebyenlarging the image of the 3D object. In another related embodiment,when the 3D object is resized in 3D space, the image of the 3D objectmay alternatively be updated in a 3D-style manner similar to the3D-style translation described above, so as to reflect the change of the3D object's perspective view after resizing. As described above, thismode is entered by selecting and dragging the camera icon from thetoolbar to a desired position on the 2D interactive surface to calculatea viewpoint. The perspective view of the scaled 3D object is thenupdated according to the calculated viewpoint.

Although in embodiments described above, the display of the rotationcontrol handles and the label boxes of a 3D object are automaticallychanged as the 3D object is scaled, in other embodiments, the display ofany of rotation control handles and label boxes of digital content, suchas for example a 2D object, may also be automatically changed when the2D object is scaled. For example, a 2D object may comprise a rotationcontrol handle for rotating the 2D object on the 2D interactive surface,and this rotation control handle may be displayed as a full or compactvisualization image if the size of the image of the 2D object is largeror smaller, respectively, than a threshold image size.

In embodiments described above, markers 62 are moved within the 3D inputspace 60 for manipulating 3D objects associated therewith. However, inother embodiments, the 3D input device 52 may also be used to captureimages of print matter in the 3D input space, in which textual andgraphical content can be recognized and then applied to digital contentaccordingly. Such print matter can be in any form, such as, for example,a book, a magazine or a paper, and the like.

The structure of the interactive input system of this embodiment is thesame as that of the interactive input system 20 described above and withreference to FIGS. 1A and 1B. The software architecture of theinteractive input system of this embodiment is illustrated in FIG. 20,and is generally identified by reference numeral 1000. Softwarearchitecture 1000 is generally the same as that of software architecture90 described above and with reference to FIG. 2, except that it furthercomprises a recognition engine 1002 and a database 1004. The recognitionengine 1002 is configured to receive the pre-processed images from theimage processing module 92, and is configured to recognize both textualand non-textual objects within the images. These textual and non-textualobjects may comprise for example text, pictures, pointers, fingers orhands.

To assist with processing the captured images and with the recognitionof textual and non-textual objects within the captured images, therecognition engine 1002 is in communication with the database 1004,which stores keywords, format descriptions and digital content objects.The digital content stored in the database 1004 comprises text, images,audio clips, video clips, URIs, email addresses, 2D and 3D digitalobjects, and other digital information that may be used. The URIs maybe, for example, hyperlinks to websites, ftp sites, news groups, SMARTNotebook™ files or other files, database queries, and the like.

The keywords and the format descriptions are used to identify thetextual objects detected from the captured images. Each keywordcomprises one or more words, symbols and/or digits, or a predefinedcharacter string. The character string may be, for example, anInternational Standard Book Number (ISBN) character string, a DigitalObject Identifier (DOI®) character string, an email address, or a webaddress. The format description describes any of a font attribute, suchas bold, italic or a size, a layout attribute, such as “align left”,“align right”, or “centered”, for example, and a format pattern ofspecial strings, such as a uniform resource indicator (URI), forexample. The keywords and the format descriptions may be predefined inthe interactive input system 20 or may be user-defined.

The pre-processed images from the image processing module 92 are sent tothe 3D manipulation module 94 for analysis and identification of anyuser gestures based on the user input in the 3D input space 60, in themanner described above. Identified user gestures are then used tomanipulate the digital content accordingly. Correspondingly, the 2Dmanipulation module 96 receives user input from the 2D interactivesurface 24, and identifies any user gestures for subsequent manipulationof the digital content.

As will be appreciated, patterns on the physical objects, such as forexample text on the print matter, can be partially or completelyoccluded by fingers or hands when the physical object is beingmanipulated, or can be out of the field of view of the camera 54, suchthat the patterns are not present in the captured images. To addressthis issue, the interactive input system 20 utilizes a method fordetecting occlusion of patterns to ensure continuous recognition of thepatterns within the captured images. The method generally comprisescomparing consecutively captured images of print matter comprising apattern to detect differences between the images. This enables theinteractive input system 20 to continue determining the pattern,regardless of the pattern not being fully present in one or more of thecaptured images.

FIG. 21 shows the steps of the continuous pattern recognition methodused by the interactive input system, and which is generally indicatedusing reference numeral 1200. A storage buffer in communication with thecomputing device 28 that stores a previously recognized image is firstcleared (step 1202), and a new image is captured by the camera 54 andtransmitted to the computing device 28 (step 1204). Next, therecognition engine 1002 recognizes textual objects and non-textualobjects, such as graphics, within the image (step 1206). In thisembodiment, the interactive input system 20 uses optical characterrecognition (OCR) techniques to perform the recognition during step1206. During OCR, the recognition engine 1002 first recognizes the textfrom the pre-processed image, and then recognizes the format associatedwith the textual object, such as the font attributes and the layoutattributes. The recognition engine 1002 also determines the image of theprint matter by identifying a generally rectangular shape image portionof the captured image encompassing recognizable matter. Font size iscategorized as large, normal or small. A normal font size is firstdetermined based on the most common height of recognized characterswithin the images, and within a defined threshold. A large font size isone for which the size of a character in the image is larger than thenormal font size by at least a threshold amount. The value of thethreshold amount can be expressed either in terms of pixels or as apercentage of size. A small font size is one for which the size of acharacter in the image is smaller than the normal font size by at leastthe threshold amount. Additional font sizes may be determined usingother threshold parameters. Non-textual objects are also recognizedduring step 1206.

Recognized objects are then associated with digital content, and theimage, the recognized objects, and any digital objects or associationsto digital objects are then stored in the memory (step 1208).

Another image is captured by the camera 54 (step 1210). The imageprocessing module 92 then pre-processes the most-recently captured image(hereafter the “current image”) (step 1212). The processing module 92determines the print matter image by identifying a generallyrectangularly-shaped image portion of the captured image encompassingrecognizable matter, calculates the angle of rotation of the image ofthe print matter, and applies the same angle of rotation to the printmatter image, as well as to the recognized textual and non-textualobjects of the stored image, so as to improve the accuracy of thecomparison. The current image is then compared with the stored image todetermine if any portions of the print matter images are different (step1214). A determination is made as to whether the pixel differencebetween identical locations of the two images is greater than athreshold (step 1216). If the difference is less than the threshold,then no further action is required; the method returns to step 1210, andthe stored image is retained. If at step 1216 the difference is greaterthan the threshold, then the current image is recognized (step 1218), asdescribed above, and recognized objects from the current image aremerged with the recognized objects of the stored image (step 1220). Themerged recognized objects are then associated with digital content (step1222), and the current image, the recognized objects, and any digitalcontent or associations to the associated digital content are stored inthe buffer, and the stored image is overwritten. The method then returnsto step 1210.

The captured images are further processed according to whether userinput has been detected. This input may be inputted in the 3D inputspace 60, for example, using a pointer, such as a user's finger. If userinput is detected in the 3D input space 60, the computing device 28interprets the input as gestures or commands for manipulating thedigital content, or as program commands. The computing device 28determines pointer gestures according to the movement of the pointer inthe 3D input space, and generates 3D input events. Similarly, thecomputing device 28 determines touch gestures based on touch events onthe 2D interactive surface 24, and generates 2D input events. Thecomputing device 28 also receives input events from other input devices,such as for example keyboard, mouse, trackball, audio input, and thelike. The input events received by the computing device 28 are passed tothe application program, which in this embodiment is SMART Notebook™,and are interpreted as one of a digital ink annotation command, anobject manipulation command, a program control command, or as anothercommand. When a command for manipulating the digital content or aprogram command is detected, the computing device 28 executes thecommand according to the user input. When the computing device 28receives a command for terminating the program, the method is terminatedaccordingly.

FIGS. 22A to 22C illustrate steps of the continuous pattern recognitionmethod 1200. FIG. 22A shows an exemplary image 1262 captured by the 3Dinput device 52. As described above, the captured image is pre-processedby the image processing module 92 to correct any optical distortions andto perform any necessary actions on the image 1262, such as imageenhancement or rotation. The recognition engine 1002 then recognizes thetextual objects 1264, 1266 and 1268, and non-textual objects, orgraphics, 1270 and 1272 from the image 1262. Next, the computing device28 recognizes that text 1266 “http://smarttech” matches the pattern of aURI because it starts with the characters “http://”. The computingdevice 28 therefore modifies the image 1262 to insert a line 1274 belowthe recognized textual object 1266, indicating that the recognized text1266 includes a hyperlink. A web link icon 1276 is also associated withthe same hyperlink, and is placed adjacent to the image of therecognized textual object 1266. Therefore, when the user actuates theicon 1276 or the recognized textual object 1266, a web browser islaunched and the user is directed to a web site indicated by theassociated URI. The recognized objects 1264, 1266, 1268, 1270 and 1272of the recognized image 1262 are then stored in the buffer.

FIG. 22B shows another image 1282 that has been captured subsequent tothe first image 1262. The computing device 28 determines that thedifference between the stored image, namely image 1262 shown in FIG.22A, and the current image, namely image 1282, is greater than athreshold. As a result, the computing device recognizes the textualobjects 1284 and 1286 of the second image 1282. The computing device 28then compares the recognized objects 1264, 1266, 1268, 1270 and 1272 ofthe recognized image 1262, to the recognized objects 1284, 1286 of therecognized image 1282 to merge the recognized objects of the two images.As the textual object 1288 of the image 1282 overlaps with, andcomprises all of the characters in the textual objects 1266 and 1268 of,the preceding recognized image 1262, the computing device 28 determinesthat the textual objects 1266 and 1268 are a subset of the textualobject 1286, and therefore the textual object 1286 is kept in the mostrecently recognized image 1282. Following the recognition of the patternof the textual object 1286, the computing device 28 modifies the image1282 to insert a line 1288 below the textual object 1286 to indicate ahyperlink, and associates the textual object 1286 and the web link icon1276 with the URI “http://smarttech.com/trainingcenter/material.asp”.The recognized objects of image 1282, together with the icon 1276 andthe associated hyperlinks, are stored in the buffer.

The process of determining whether or not recognized objects insubsequently-captured images are to be merged is repeated, as necessary,in accordance with the continuous pattern recognition method 1200. Forexample, FIG. 22C shows another image 1302 that has been capturedsubsequent to image 1282. The recognized objects of image 1302 comprisetextual objects 1304 to 1310 and a non-textual object 1312. Thecomputing device 28 compares the recognized objects in the tworecognized images 1282 and 1302, and determines that the textual object1304 of FIG. 22C is identical to the textual object 1284 of FIG. 22B,and the textual object 1304 is therefore maintained within the currentlyrecognized image 1302. The computing device 28 also determines that thetextual objects 1306 to 1310 contain a subset of characters found in thetextual object 1286, as the other characters are obscured by thenon-textual object 1312, namely a user's finger. Using thisdetermination, the computing device 28 merges the recognized objects1306 to 1310 of image 1302 and the recognized objects of image 1282, bysubstituting the textual objects 1306 to 1310 with the previouslyrecognized textual object 1286, and thus recognizes the URI“http://smarttech.com/trainingcenter/material.asp”. The computing device28 then modifies the image 1302 to insert a line 1314 below the textualobjects 1306 to 1310, and updates the hyperlink associated with the weblink icon 1276 with the aforementioned URI. The images of the textualobjects 1306 to 1310 are also set as hyperlinks comprising the same URI.The recognized objects of image 1302, along with the icon 1276 andassociated hyperlinks are stored in the buffer.

As will be appreciated, by recognizing textual and non-textual objectsfrom captured images in the 3D input space, the interactive input system20 superimposes digital objects on the captured images and displaysthese modified images on the 2D interactive surface 24. The user maymanipulate the print matter image and the superimposed digital objectsby inputting any of 3D gestures in the 3D input space 60 and touchgestures on the 2D interactive surface 24. The interactive input system20 then detects user input from the 3D input space 60 and/or the 2Dinteractive surface 24, and manipulates the modified images accordingly.

FIGS. 23A to 23C illustrate examples of manipulation of the print matterimages and the superimposed digital objects using gestures performed inthe 3D input space. FIG. 23A shows a captured image 1362 that has beenreceived by the computing device 28. The computing device 28 recognizesthe textual objects and non-textual objects in the image 1362 anddetects the formats thereof. For example, a textual object comprising acharacter string 1364 is recognized as the words “CHAPTER II.” Also,given the capitalized characters, the comparatively larger font size,and the position relative to the remainder of the textual object 1367,the character string 1364 is thus recognized as a chapter title.Therefore, the computing device 28 places a box 1366 around thecharacter string 1364. The box 1366 defines an area, or a “hot zone”,that serves as a hyperlink to predefined digital content. As an example,the digital content may be a SMART Notebook™ file stored on thecomputing device 28. In this embodiment, the computing device 28 alsoprovides an icon 1368 comprising the same hyperlink associated with thecharacter string 1364.

The computing device 28 continues to recognize the remainder of thetextual object 1367, and determines that a character string 1370 refersto the word “Rome”. The computing device 28 also determines the fontattributes of the character string 1370. Based on the width of thecharacters of character string 1370 as compared to the width of thecharacters of the remainder of the textual object 1367, the characterstring 1370 is identified as having a “bold” font. According topredefined rules, the computing device 28 interprets the bold characterstring 1370 as a recognizable pattern and associates it with digitalcontent, namely an icon 1372 that is superimposed adjacent to the imageof the string 1370. In this embodiment, the icon 1372 is hyperlinked toa search engine, such that actuation of the hyperlink initiates a searchquery related to the term “Rome”.

The computing device 28 also determines that the character string 1374“Colosseum” matches a predefined keyword. Therefore, for each occurrenceof the character string 1374, a line 1376 is inserted underneathindicating a link to digital content, such as a 3D model, and an icon1378 comprising the same link to the digital content is superimposedadjacent to the character string 1374. The area immediately surroundingeach character string 1374 in the recognized image 1362 is set as a hotzone comprising the same link to the digital content.

FIG. 23B shows another image 1402 captured by the 3D input device 52subsequent to the first image 1362. As described above, the computingdevice 28 compares the image 1402 with the previously recognized image1362 of FIG. 23A, in order to determine any differences therebetween. Asthe difference between the two recognized images 1362 and 1402 is largerthan a threshold due to the presence of a pointer in the image 1402, theimage 1402 is recognized. The computing device 28 determines that therecognized image 1402 comprises a non-textual object 1404 that is notpresent in the previously recognized image 1362. The computing device 28then determines that the non-textual object 1404 is most likely apointer, and therefore calculates the envelope of the non-textual object1404 and detects the pointer tip 1408. The recognized textual objectscorresponding to the respective images 1362 and 1402 are then merged,and the digital content, the icons and the associated hyperlinks arestored with the image 1402.

The computing device 28 then calculates the position of the pointer tip1408 and determines that the pointer tip 1408 superimposes an area 1406already identified as a hot zone associated with the character string1374 “Colosseum”. Typically, the placement of a pointer tip 1408 on ahot zone 1406 for a predefined time indicates a user's desire to actuatethe hyperlink to the associated digital content. Accordingly, thecomputing device 28 sets out to determine whether the placement of thepointer tip 1408 is of a transient or non-transient nature. For example,if the pointer tip 1408 was captured while the image of the print matterwas being acquired, then the user probably had no intention to actuatethe hyperlink. Conversely, if the comparison successive images showsdwelling of the pointer tip 1408 over the area 1406, then the computingdevice 28 determines that the user expects to follow the hyperlink tothe associated content. Accordingly, the computing device 28 displays atime indicator 1410 adjacent to the pointer tip 1408 and starts a timerto determine the dwell time of the pointer tip 1408 on the hot zone1406. If the pointer tip 1408 is maintained over the hot zone 1406 for atime period longer than a threshold time period, the hyperlink isactuated. Upon actuation of this link, the hyperlinked digital content1412, such as a 3D digital object of the Colosseum in the example shown,is displayed on the 2D interactive surface 24, as shown in FIG. 23C.

The digital content 1412 may be manipulated via gestures in the 3D inputspace 60 only, and without any interaction with the 2D interactivesurface 24. For example, FIG. 24A shows an example of a user positioninga fingertip 1444 at a position in the 3D input space 60 such that theimage of the fingertip 1444 overlaps the digital content 1412 in thecaptured image 1442. Accordingly, the computing device 28 sets out todetermine whether the fingertip 1444 positioning is of a transient ornon-transient nature, in order to determine whether or not the userintends to manipulate the digital content 1412. The computing device 28therefore displays another time indicator (not shown) adjacent to thefingertip 1444, and starts a timer to determine the dwell time of theuser's fingertip 1444 on the digital content 1412. If the fingertip 1444is maintained over the digital content 1412 for a time period longerthan a threshold time period, the computing device 28 determines thatthe user intends to manipulate the digital content 1412 and displays avertical scroll bar 1446 and a horizontal scroll bar 1448 adjacent thedigital content 1412 to facilitate its manipulation. In this example,the vertical scroll bar 1446 is associated with size resizingfunctionality, while the horizontal scroll bar 1448 is associated withrotational functionality of the digital content 1412. For example, inFIG. 24B, the user has moved the finger such that the fingertip 1444 ispositioned generally over the vertical scroll bar 1446 in the 3D inputspace 60. Translation of the fingertip 1444 between the ends of thevertical scroll bar 1446 results in zooming into and out of the 3Ddigital content 1412. Translation of the fingertip 1444 between the endsof the horizontal scroll bar 1448 results in rotation of the 3D digitalcontent 1412 on a plane perpendicular to the 2D interactive surface 24,as shown in FIG. 24C.

Other gestures may be performed in the 3D input space 60 and interpretedby the computing device 28 for manipulation of the URIs, the digitalcontent and the captured image. For example, the user may apply twofingers over print matter in the 3D input space 60 and then move themapart in order to zoom into the captured image of the print matter.Conversely, moving the two fingers towards each other results in zoomingout of the captured image. For example, FIG. 25A shows an image 1500captured by the 3D input device 60 that has been detected and is shownin a window 1519. Textual objects and non-textual objects of the image1500 are recognized, digital contents 1502 to 1508 are superimposed onthe recognized image 1500, and a line 1510 is inserted under certainrecognized character strings, namely “Colosseum” in the embodimentshown. Two fingers 1512 and 1514 positioned in the 3D input space 60 bythe user are moved apart, as denoted by the two arrows 1516 and 1518, tozoom into the captured image 1500. The computing device 28 identifiesthis zooming gesture, and then magnifies the captured image 1500 andplaces a vertical scroll bar 1522 and a horizontal scroll bar 1524 alongthe edges of the window 1519, as shown in FIG. 25B. The scroll bars 1522and 1524 enable a user to pan through the zoomed image to view differentportions of the image 1500 within the window 1519. Moving a slider 1526of the vertical scrollbar 1522 in one direction causes the contentwithin the window 1519 to scroll vertically in the opposite direction.Similarly, moving a slider 1528 of the horizontal scrollbar 1524 in onedirection causes the content within the window 1519 to scrollhorizontally in the opposite direction. In this embodiment, the zoom inand zoom out gestures only alter the size of the textual and non-textualobjects, leaving the size of the superimposed digital content, such asicons, pictures and 3D objects, unchanged.

FIG. 26 shows an example of a captured image 1602 of a typical prefaceof a publication received by the computing device 28. The computingdevice 28 recognizes textual and non-textual objects within the image1602 in the manner described above. In the example shown, the computingdevice 28 detects the character string 1603 comprising a characterstring “DOI” followed by some digits, and determines that the characterstring 1603 corresponds to, and therefore represents, a naming scheme ofthe Digital Object Identifier (DOI®) System for identifying digitalcontent objects. The computing device 28 then automatically executes asearch in a DOI database, with which it is in communication, to findcontent associated with the DOI number 1603. If, for example, thecontent is a publication, then the search returns information about theauthor, the publisher, the publishing date and the abstract, among otherinformation. The computing device 28 also recognizes the characterstring “CONTENTS” 1604, and that the textual object 1606 includes aplurality of lines of text ending with a numeral. The computing device28 determines that this combination of items is in the form of a tableof contents, and then searches information of each entry of therecognized table of contents using the text 1606 and the DOI number1603. An underline 1608 is inserted under each line of text 1606, andeach underline 1608 is set as a hot zone comprising a hyperlink to therelevant information found by the search. A box 1609 is superimposedaround the DOI number 1603, and an icon 1610 is also superimposed theimage 1602 adjacent to the DOI number 1603. The icon 1610 is hyperlinkedto the content associated with the DOI number 1603.

The computing device 28 also recognizes the character string 1612, andanalyzes the character string 1612 and adjacent textual object 1614 andnon-textual object 1618, and determines that the character string 1612refers to the name of the author and that the non-textual object 1618 isthe picture of the author, using semantic technology or other suitablemethods. A local or remote search for the author's name 1612 issubsequently conducted. In this example, entries matching the author'sname 1612 are uncovered, such as a Facebook™ related URI and a Twitter™related URI. The computing device 28 then superimposes an underline 1616below the author's name 1612, and associates the author's name 1612 withthe author's picture 1618. A Facebook icon 1620 and a Twitter icon 1622are also superimposed adjacent to the author's picture 1618, and eachicon 1620 and 1622 is hyperlinked to its respective URI.

Character strings that are recognized in images may be selected byusers. For example, FIG. 27A shows a captured image 1682 comprising acharacter string 1680 corresponding to the word “first”. To select thecharacter string 1680, a pointer 1684, such as a user's finger, ispointed to the word 1680 and is moved over the word 1680. The computingdevice 28 recognizes this action as a selection gesture. The computingdevice 28 then conducts a search for any other occurrence of theselected word 1680 within the recognized image 1682, and superimposes ahighlight color 1688 on each match 1686, including the instance of thecharacter string 1680 selected by the user. If the pointer 1684 dwellsover the word 1680 for longer than a threshold time period, then thecomputing device 28 launches a local or remote dictionary search to findthe definition of the word 1680. Here, the computing device 28superimposes a time indicator (not shown) adjacent the pointer 1684, andstarts a timer to determine the dwell time of the pointer 1648. When thedwell time exceeds a threshold time, the dictionary search is thenlaunched. The results of the dictionary search are then displayedadjacent the word 1680 as a bubble 1692 superimposed on the image 1682,as shown in FIG. 27B.

Selection gestures may be used to launch other relevant applicationprograms. For example, FIG. 28 shows a captured image 1700 that isrecognized, and in which characters 1702 are interpreted as numeralsrepresenting a number. When a user performs a selection gesture on therecognized number 1702 using a finger 1704, as described above, thecomputing device 28 superimposes a highlight color 1706 on the selectednumber 1702 and launches a calculator application program 1708, which issuperimposed on the image 1700. The selected number 1702 is then shownin an input portion 1710 of the calculator program 1708.

FIGS. 29A and 29B show a view change feature provided by the interactiveinput system 20. Here, a software button (not shown) is selectable forcausing the computing device 28 to transform a captured image 1772 froma plan view to a 2D perspective view. The captured image 1772 isdisplayed on the 2D interactive surface 24 as a plane of a virtual 3Dspace, with hyperlinks and digital content superimposed on the image1772. For example, referring to FIGS. 24A and 29A, hyperlinked digitalcontent, such as a 3D object 1774, is shown in the virtual 3D space andis displayed on the 2D interactive surface 24. The user then selects the3D object 1774, and a “vertical” scroll bar 1776 and a “horizontal”scroll bar 1778 are placed adjacent to the 3D object 1774. The user mayslide a finger 1780 in the 3D input space 60 on the “horizontal” scrollbar 1778 to rotate the 3D object 1774, as shown in FIG. 29B.Alternatively, the user may slide the finger 1780 in the 3D input space60 on the “vertical” scroll bar 1776 to zoom in or zoom out the 3Dobject 1774.

In other embodiments, the links and the digital content mayalternatively be manipulated by a user through interaction with the 2Dinteractive surface 24 using a pointer. In these embodiments, the 2Dinteractive surface 24 detects pointer contacts thereon, and generatescontact events, such as pointer-up, pointer-down, pointer-move, togetherwith the coordinates of the contacts. The contact events arecommunicated to the computing device 28, which determines gestures, andthen translates the contact events and the gestures into commands formanipulating the links and digital content.

The 3D input device is not limited to that described above, and in otherembodiments, other 3D input devices may be used. For example, FIG. 30Ashows another embodiment of a 3D input device, which is generallyindicated by reference numeral 1802. 3D input device 1802 comprises acamera 1804 mounted to a base 1808 via an articulated arm 1806. Similarto the 3D input device 52 described above and with reference to FIG. 1A,the camera 1804 has a field of view of a 3D input space 60 within whichprint matter 1810 is located. The 3D input device 1802 also comprises alight projecting component 1812 that projects light towards the bottomplane 1814 of the 3D input space 60. In this embodiment, the lightprojecting component 1812 is a digital projector. The light projectingcomponent 1812 projects the same links and digital contents onto theprint matter 1810 in the 3D input space 60 as those which aresuperimposed on captured images (not shown) that are displayed on the 2Dinteractive surface 24. The light projecting component 1812 projectsdigital content 1816 onto the bottom plane 1814 of the 3D input space60, and this same digital content is also projected onto the 2Dinteractive surface 24 (not shown). The projected digital content 1816superimposes the print matter 1810 at the appropriate coordinates on theprint matter 1810 corresponding to the location coordinates on thecaptured image displayed 2D interactive surface 24.

The 3D input device 1802 is also configured to detect the location ofthe tip of a pointer as described before, in a manner similar to 3Dinput device 52 described above and with reference to FIG. 1A. Upondetection of the location of the pointer tip, the projecting device 1812then projects a mark 1820 onto the print matter 1810 at the detectedpointer tip location to aid the user with manipulation. In theembodiment shown, the mark 1820 is a crosshairs image.

Turning now to FIG. 31, a stereoscopic interactive input system having athree-dimensional (3D) input space according to another embodiment isshown and is generally identified by reference numeral 2000. Theinteractive input system 2000 is generally similar to the interactiveinput system 20 described above and with reference to FIG. 1A. For easeof description, the components of interactive input system 2000 that arethe same as those of interactive input system 20 are identified usingthe same reference numerals as in FIG. 1A, and are not described below.

In this embodiment, the projector 2002 is a 3D-capable projector that iscapable of projecting a 3D image onto the 2D interactive surface 24. Byusing 3D glasses 2004, the user is able to view stereoscopic 3D imagesof digital content 2006 displayed on the 2D interactive surface 24. The3D glasses 2004 provide the user with a sense of depth perception forthe displayed digital content 2006.

The interactive input system 2000 also comprises one or more proximitysensors that are configured for sensing the presence of objects, such asa user, in proximity with the interactive board 22. The proximitysensors are in communication with the master controller accommodated bythe tool tray 48. In this embodiment, a first pair of proximity sensors2008 and 2010 are mounted on an underside of the interactive board 22,with each sensor 2008 and 2010 being positioned adjacent a differentrespective bottom corner 22 a and 22 b of the interactive board, and asecond pair of proximity sensors 2012 and 2014 mounted on an undersideof the tool tray 48 adjacent the detachable tool tray modules 48 a and48 b received by opposite ends of the tool tray. The distance betweenthe sensors 2012 and 2014 is selected to be greater than the width of anaverage adult person. Further specifics of the proximity sensors andtheir mounting locations on the tool tray 48 are described in PCTApplication No. PCT/CA2011/000657 to Tse et al., filed on Jun. 6, 2011,and entitled “INTERACTIVE INPUT SYSTEM AND METHOD”, the content of whichis incorporated herein by reference in its entirety.

Similar to the interactive input system 20 described above, when amarker 62 is brought into the 3D input space 60 and is captured in animage acquired by the camera 54, the computing device 28 recognizes apattern on the marker 62, and associates the marker with digital contentor a digital tool. For example, FIG. 31 shows the marker 62 that isassociated with digital content 2006 in the form of a stereoscopic 3Dgraphic object representing a stadium.

FIG. 32 is a block diagram illustrating the architecture of theinteractive input system 2000, and which enables 3D content to begenerated. In this embodiment, the architecture is embodied in thecomputing device 28, and comprises an input handling module 2084, a 3Drendering engine 2086 and a stereo 3D graphics card 2088. The inputhandling module 2084 receives 3D content manipulation input from variousinput devices such as the camera 54, the interactive whiteboard 22, themouse, keyboard or other suitable input device, and instructs the 3Drendering engine 2086 to produce an image that is based on stored 3Ddata in a manner well known to those skilled in the art. The 3D data isthen processed by the stereo 3D graphics card 2088 and a left eye image2090 and a right eye image 2092 are generated for viewing by the leftand right eyes, respectively, of the user. The left eye image 2090 isgenerally offset from the right eye image 2092 with the amount of offsetdetermining the 3D depth of the object. The left eye and right eyeimages 2090 and 2092 are then sent to the projector 2002, whichalternately projects the left eye and right eye images 2090 and 2092 onthe 2D interactive surface 24 rapidly. Although not shown, the 3Dglasses 2004 comprise active shutters that control the opaqueness of thetwo lenses of the glasses 2004. When the glasses 2004 are turned off,the shutters are conditioned to a state such that both lenses aretransparent, thereby allowing both eyes of the user to see through theglasses. When the glasses 2004 are turned on, the shutters areconditioned to switch on and off in synchronization with the timing andfrequency of the alternately projected left eye and right eye images2090 and 2092 on the 2D interactive surface 24. Therefore, when the lefteye image 2090 is projected on the 2D interactive surface 24, theleft-eye shutter of the glasses 2004 is transparent and the right-eyeshutter of the glasses 2004 is opaque, so that only the user's left eyesees the left eye image 2090. Similarly, when the right eye image 2092is projected on the 2D interactive surface 24, the left-eye shutter ofthe glasses 2004 is opaque and the right-eye shutter of the glasses 2004is transparent so that only the user's right eye sees the right eyeimage 2092. As a result, the user senses the illusion of 3D content.

FIGS. 33A to 33D illustrate a method of manipulating of a 3D object onthe two-dimensional 2D interactive surface 24. In FIG. 33A, 3D content2006 in the form of a stereoscopic graphic object representing a stadiumis displayed on the interactive board 22 and is visible to the userwearing the 3D glasses 2004. By virtue of the operation of the 3Dglasses 2004, to the user, the 3D content appears to hover above theinteractive board 22. In FIG. 33B, the user approaches the interactiveboard 22. As the user approaches a predefined proximity of theinteractive board 22, the user's presence is detected by one or more ofthe proximity sensors 2008, 2010, 2012 and 2014. The computing device 28in response to proximity sensor output modifies the image outputprovided to the projector 2002 so that the hovering graphic object 2006reduces in size and transitions to a graphic object 2006 on the plane ofthe 2D interactive surface 24 through a smooth animation to provide theuser with the illusion that the graphic object 2006 has moved down tothe 2D interactive surface 24. When a pointer 122 operated by the usertouches the graphic object 2006 on the 2D interactive surface 24, agraphic object manipulation tool in the form of a selection box 2112 asdescribed above is presented on the 2D interactive surface 24surrounding the graphic object 2006. The user may touch the graphicobject 2006 or one or more of the control handles on the selection box2112 to manipulate the graphic object 2006. For example, as shown inFIG. 33C, the pointer 122 has moved the graphic object 2006 to the topright corner of the interactive board 22 and has also manipulated thepoint of view of the graphic object 2006. In FIG. 33D, as the pointer122 has moved beyond the predefined proximity of the interactive board22, the computing device 28 modifies the image output provided to theprojector 2002 so that the graphic object 2006, through a smoothtransition animation as seen by the user wearing the 3D glasses 2004,“floats” from the plane of the 2D interactive surface 24 to a hoveringstate at a position and perspective corresponding to the last positionof the graphic object 2006 on the plane of the 2D interactive surface24.

If there is more than one 3D graphic object hovering above the 2Dinteractive surface 24, all 3D graphic objects transition to the planeof the 2D interactive surface 24 when the user approaches the predefinedproximity of the interactive board 22. Of course, if desired, in analternative embodiment, if there is more than one 3D graphic objecthovering above the 2D interactive surface 24, only graphic objectswithin the user's proximity transition to the plane of the 2Dinteractive surface 24 while the rest remain hovering above the 2Dinteractive surface 24.

FIG. 34 shows the steps performed during manipulation of 3D graphicobjects on a 2D surface such as 2D interactive surface 24. The processbegins with a stereoscopic 3D graphic object 2006 being projected on the2D interactive surface 24 and the 3D glasses 2004 worn by the userturning on and operating to create the stereoscopic effect (step 2132).As a result, the graphic object appears to hover over the interactiveboard 22. The computing device 28 then performs a check to determine ifa user has entered the predefined proximity of the 2D interactivesurface 24 as detected by one or more of the proximity sensors (step2134). If there is no user within the predefined proximity of the 2Dinteractive surface 24, then the display of the 3D graphic objecthovering above the interactive board 22 continues and the process loopsto again check to determine if a user has entered the predefinedproximity. When a user is detected within the predefined proximity, thestereoscopic 3D graphic effect is turned off (step 2136). At this step,an animation is produced showing the 3D object smoothly transitioningfrom its hovering state above the 2D interactive surface 24 to alocation on the plane of the 2D interactive surface 24 (e.g., byreducing the offset between the left eye and right eye images 2090 and2092 and by reducing the size of the graphic object). When the left eyeand right eye images 2090 and 2092 become identical, the stereoscopic 3Deffect is effectively turned off. Optionally, the 3D glasses 2004 mayalso be turned off or be conditioned to set both shutters to on. Thecomputing device 28 then processes any gestures or actions that havebeen made by the user interacting with the graphic object 2006 (step2138). The flowcharts showing the steps performed in response tomanipulation gestures are illustrated in FIGS. 11A to 11E. A check isthen made by the computing device 28 to detect if the user is stillwithin the predefined proximity of the 2D interactive surface 24 (step2140). If the user is still present, then the image output provided tothe projector 2002 will still appear on the same plane as the 2Dinteractive surface 24 and the user can continue to manipulate thegraphic object. If the user is no longer within the predefinedproximity, the stereoscopic effect of the 3D glasses 2004 is turned backon (step 2132) with an animation produced showing the manipulated 3Dgraphic object 2006 transitioning back to a hovering state above theinteractive board 22.

Those skilled in the art will understand that actions and manipulationscan include, e.g., moving the object, rotating the object, changing the“distance” between the object and the 2D interactive surface 24 byresizing the object, and the like. Those skilled in the art will alsounderstand that more than one touch may be used to complete thegestures.

In an alternative embodiment, instead of using proximity detection, thecomputing device 28 may turn the stereoscopic effect of the 3D glasses2004 on and off based on touch. For example, when the user touches the2D interactive surface 24, the stereoscopic effect of the 3D glasses isturned off with the graphic object animating to “land” on the 2Dinteractive surface 24 at the touch location. The user may thenmanipulate the graphic object. When no touch on the 2D interactivesurface 24 is detected for a threshold amount of time, the stereoscopiceffect of the 3D glasses 2004 is turned on with the graphic objectanimating to a hovering state above the interactive board 22.

FIGS. 35A to 35D show yet another embodiment of direct manipulation of a3D graphic object on a 2D interactive surface 24 through stereo tractorbeam interaction. In FIG. 35A, a halo 2162 appears on the 2D interactivesurface 24 beneath the 3D graphic object 2164. In FIG. 35B, when thepointer 122 touches the halo 2162, the stereoscopic 3D effect is turnedoff with an animation produced showing the graphic object 2164 smoothlytransitioning from a hovering state above the 2D interactive surface 24to a “landing” state on the plane of the 2D interactive surface 24 atthe user's touch location. In FIG. 35C, the pointer 122 manipulates thegraphic object 2164. In FIG. 35D, the user is no longer manipulating thegraphic object 2164 (e.g., not touching the 2D interactive surface 24for a threshold period of time). As a result, the 3D graphic object 2164transitions to the hovering state above the interactive board 22,through a smooth animation.

FIGS. 36A and 36B show yet another alternative manipulation techniquethat makes use of the proximity sensors. In FIG. 36A, the user wearingthe stereoscopic 3D glasses 2004 is viewing the 3D graphic object 2006from the left side of the interactive board 22. The proximity sensors(not shown) detect the area where the user is currently standing. InFIG. 36B, the proximity sensors (not shown) detect that the user wearingthe stereoscopic glasses 2004 has moved to the right side of theinteractive board 22. In response, the computing device 28 moves the 3Dgraphic object 2006 towards the right side of the 2D interactive surface24, through a smooth animation.

In an alternative embodiment, proximity sensors can be used to detectthe position of the user. By tracking the position of the user's fingerand position of their body with a time-of-flight (TOF) camera forexample, 3D graphic objects selected by the user can be determined andhighlighted.

FIG. 37 shows direct manipulation of 3D content with a dual displayconfiguration according to another embodiment. In this embodiment, ahorizontal 2D interactive surface 2422 displays a graphic object 2426. Avertical display 2424 that is proximate surface 2422 displays athree-dimensional stereoscopic view 2428. As the pointer 122 manipulatesthe graphic object 2426 on the 2D interactive surface 2422, the 3D view2428 presented on the vertical display 2424 is adjusted accordingly. Inthis embodiment, the graphic object displayed on the 2D interactivesurface 2422 is an interactive map or building layout that can bemanipulated while the vertical display produces a 3D street level viewof a portion of the map or building layout.

Although in the embodiment shown in FIGS. 3A to 4B, the translation of a3D object may be conditioned to the 3D translation mode by applying acamera icon to a desired location of the 2D interactive surface 24, orconditioned to the 2D translation mode by removing the camera icon fromthe 2D interactive surface 24, in some alternative embodiments, othermethods may be used to condition the translation of 3D objects to 3D or2D translation mode, e.g., by checking or unchecking a 3D/2D translationmode option. In yet some other embodiments, the translation of 3Dobjects is always conditioned to 2D translation mode or 3D translationmode. In still some other embodiments, the translation mode of 3Dobjects is related to the canvas page. Thus, if the host applicationprogram (e.g., SMART Notebook™) comprises multiple canvas pages, theuser may set each page to a desired translation mode, and differentpages may be set to different translation modes.

Although in the above embodiments, the interactive board 22 is describedas being mounted on a vertical support surface, those skilled in the artwill appreciate that the interactive board may be supported on a standor other suitable framework or suspended from overhead architecture. Ofcourse interactive boards employing other machine vision configurations,analog resistive, electromagnet, capacitive, acoustic or othertechnologies to register pointer input may be employed. Also, ratherthan taking a vertical configuration, the interactive board may be inthe form of a touch table comprising a horizontally oriented 2Dinteractive surface.

Although in above embodiments, the 3D input space is defined as apyramidal frustum shape, those skilled in the art will appreciate thatthe 3D input space may take other 3D shapes such as for example, a cube,a cylinder or a sphere. In this case, the planes are also properlydefined according to the shape of the 3D interactive space, and may notnecessarily be a flat plane.

Those skilled in the art will appreciate that variations of inputdevices can be utilised. Input devices can include an interactivewhiteboard, an interactive table, and interactive tablets.

Those skilled in the art will appreciate that in some alternativeembodiments, the selection box of a 3D object may comprise differentrotation control handles. For example, in one alternative embodiment,the selection box of a 3D object may only comprise an x-rotation controlhandle. In another alternative embodiment, the selection box of a 3Dobject may only comprise a y-rotation control handle. In yet anotheralternative embodiment, the selection box of a 3D object may comprisex-, y- and z-rotation control handles but no arcball free-rotationcontrol handle. In still an alternative embodiment, users may be allowedto customize what rotation control handles shall be displayed.

Those skilled in the art will also appreciate that some control regionsmay not comprise representative images (i.e., the image of controlhandles). Also, the control regions defined in the selection box of a 3Dobject may vary depending on system design. User may be allowed tocustomize what control regions shall be included in the selection box ofa 3D object.

Although in embodiments described above, the icon associated with abolded character string is hyperlinked to a search engine, such thatactuation of the hyperlink initiates a search query related to the termin that character string, in other embodiments, the icon mayalternatively be hyperlinked to images related to the term in thatcharacter string. In still other embodiments, the area immediatelysurrounding the character string may be set as a hot zone comprising thehyperlink associated with the icon.

Although in embodiments described above, the zoom in and zoom outgestures only alter the size of the textual and non-textual objects,leaving the size of the superimposed digital content, such as icons,pictures and 3D objects, unchanged, in other embodiments, the zoom inand zoom out gestures may alternatively resize the superimposed digitalcontent proportionally when the image is resized.

Although in embodiments described above, the 3D input device comprises aprojecting device that projects a crosshairs image onto the print matterat a detected pointer tip location to aid a user with manipulation, inother embodiments, the projecting device of the 3D input device mayalternatively comprise a laser device controlled by the computing devicethat projects a laser beam onto the print matter at the detected pointertip.

Although embodiments have been described above with reference to theaccompanying drawings, those skilled in the art will appreciate thatvariations and modifications may be made without departing from thescope thereof as defined by the appended claims.

1. A non-transitory computer-readable medium having computer-executableinstructions embodied thereon that, when executed by a computing device,facilitate a method comprising: displaying a two-dimensional (2D) imageof a three-dimensional (3D) object on a display; defining at least oneregion on said display for controlling the rotation of said 3D objectabout a defined axis, said axis being parallel to a display surface ofsaid display; receiving input applied to said at least one region;determining, from said input, a rotation direction; and modifying saiddisplayed 2D image by rotating said 3D object about the defined axisalong said rotation direction.
 2. The method of claim 1 furthercomprising: displaying at least one visual indication in said at leastone region.
 3. The method of claim 2 wherein said at least one regioncomprises a first region and a second region, for controlling therotation of said 3D object about a defined first axis and a definedsecond axis, respectively, the first and second axes being parallel tosaid display surface and being orthogonal.
 4. The method of claim 3wherein said at least one visual indication comprises arcs, each arcindicating a respective rotation direction about a respective one ofsaid first and second axes.
 5. The method of claim 4 wherein each ofsaid arcs comprises an arrow at each end thereof.
 6. An interactiveinput system comprising: a display comprising a display surface on whicha two-dimensional (2D) image of a three-dimensional (3D) object and atleast one region for controlling rotation of said 3D object about adefined axis are presented; and computing structure communicating withsaid display, said computing structure, in response to input applied tosaid at least one region, determining a rotation direction and modifyingsaid 2D image by rotating said 3D object about said defined axis in saidrotation direction.
 7. The interactive input system of claim 6 whereinat least one visual indication is presented in said at least one region.8. The interactive input system of claim 7 wherein said at least oneregion comprises a first region and a second region, for controlling therotation of said 3D object about a defined first axis and a definedsecond axis, respectively, the first and second axes being parallel tosaid display surface and being orthogonal.
 9. The interactive inputsystem of claim 8 wherein said at least one visual indication comprisesarcs, each arc indicating a respective rotation direction about arespective one of said first and second axes.
 10. The interactive inputsystem of claim 9 wherein each of said arcs comprises an arrow at eachend thereof.
 11. An interactive input system comprising: computingstructure; a display in communication with said computing structure,said display presenting an image comprising digital content; and aninput device detecting at least one physical object carrying arecognizable pattern within a three-dimensional (3D) input space andproviding output to said computing structure, said computing structurebeing configured to process the output of the input device to: recognizethe pattern carried by the at least one physical object in the 3D inputspace; and modify the image presented on the display based on at leastone of the detected state of the at least one physical object and theproximity of a user to a designated location.
 12. The interactive inputsystem of claim 11 wherein the designated location is the display. 13.The interactive input system of claim 11 wherein the computing structuretransitions a displayed object from a three-dimensional hover positionto a position on the plane of a display surface of the display when theuser is proximate the designated location.
 14. The interactive inputsystem of claim 13 wherein the image comprises interactive tools forenabling user interaction with the displayed object.
 15. The interactiveinput system of claim 14 wherein the interactive tools comprise at leastone of object manipulation tools and object annotation tools.
 16. Anon-transitory computer-readable medium having computer-executableinstructions embodied thereon that, when executed by a computing device,facilitate a method comprising: presenting an image comprising digitalcontent on a display surface; recognizing a pattern carried by aphysical object placed within a three-dimensional input space; andmodifying the image based on at least one of the detected state of theat least one physical object and proximity of a user to a designatedlocation.
 17. The method of claim 16 wherein the designated location isthe display.
 18. The method of claim 16 further comprising transitioninga displayed object from a three-dimensional hover position to a positionon the plane of said display surface when the user is proximate thedesignated location.
 19. The method of claim 18 wherein the imagecomprises interactive tools for enabling user interaction with thedisplayed object.
 20. The method of claim 19 wherein the interactivetools comprise at least one of object manipulation tools and objectannotation tools.
 21. A computerized method comprising: displaying anenclosure around the periphery of a displayed graphic object uponselection of the graphic object, the enclosure having control elementsassociated therewith; and manipulating the graphic object according touser interaction with at least one of said control elements.
 22. Themethod of claim 21 wherein said control elements comprise at least oneof rotation control elements and resizing control elements, and whereinsaid manipulating comprises at least one of rotating and resizing thedisplayed graphic object.
 23. The method of claim 22 further comprising,upon user interaction with one of the rotation control elements,removing the enclosure while maintaining the rotation control element.24. The method of claim 22 wherein said control elements comprise aplurality of rotation control elements each associated with a differentrespective axis, and wherein said manipulating comprises rotating thegraphic object about the axis associated with the rotation controlelement interacted upon by the user.
 25. The method of claim 24 whereinsaid control elements further comprise a free rotation tool and whereinsaid manipulating comprises rotating the displayed graphic object inaccordance with user interaction with said free rotation tool.
 26. Themethod of claim 25 wherein said free rotation tool comprises asnap-to-axis function.
 27. The method of claim 21 further comprisingchanging the visual appearance of the control elements upon resizing ofthe graphic object or the enclosure.
 28. An interactive input systemcomprising: a display comprising a display surface on which at least onegraphic object is presented; and computing structure communicating withsaid display, said computing structure being configured to cause saiddisplay to present an enclosure having control elements associatedtherewith around the periphery of a selected graphic object and tomanipulate the graphic object according to user interactions with atleast one control element of said enclosure.
 29. The interactive inputsystem of claim 28 wherein said control elements comprise at least oneof rotation control elements and resizing control elements.
 30. Theinteractive input system of claim 29 wherein said computing structure isconfigured, upon user interaction with one of the rotation controlelements, to remove the enclosure while maintaining the rotation controlelement.
 31. The interactive input system of claim 28 wherein saidcontrol elements comprise a plurality of rotation control elements eachassociated with a different respective axis, and wherein said computingstructure is configured to rotate the graphic object about the axisassociated with the rotation control element interacted upon by theuser.
 32. The interactive input system of claim 31 wherein said controlelements further comprise a free rotation tool and wherein saidcomputing structure is configured to rotate the displayed graphic objectin accordance with user interaction with said free rotation tool. 33.The interactive input system of claim 32 wherein said free rotation toolcomprises a snap-to-axis function.
 34. The interactive input system ofclaim 28 wherein said computing structure is further configured tochange the visual appearance of the control elements upon resizing ofthe graphic object or the enclosure.
 35. A non-transitorycomputer-readable medium having computer-executable instructionsembodied thereon that, when executed by a computing device, facilitate amethod comprising: designating one or more anchor points on a displayedgraphic object; anchoring a label box to one or more said anchor points;and annotating said label box.
 36. The method of claim 35 furthercomprising expanding or collapsing said label box according to the sizeof said graphic object.
 37. An interactive input system comprising: adisplay comprising a display surface; and computing structurecommunicating with said display, said computing structure beingconfigured to: designate one or more anchor points on a graphic objectpresented on said display surface; anchor a label box to one or moresaid anchor points; and annotate said label box.
 38. A non-transitorycomputer-readable medium having computer-executable instructionsembodied thereon that, when executed by a computing device, facilitate amethod comprising: capturing an image of a three-dimensional (3D) inputspace and recognizing at least one object therein; capturing anotherimage of said 3D input space and recognizing at least one objecttherein; comparing the captured images to determine a differencetherebetween; when said difference is greater than a differencethreshold, merging the recognized objects to form a composite recognizedobject and storing said composite recognized object; when saiddifference is not greater than said difference threshold, storing one ofsaid recognized objects and discarding the other of said recognizedobjects; and associating either said stored composite recognized objector said stored one recognized object with digital content.
 39. Themethod of claim 38 wherein during said one recognized object storing,the recognized object having the most recognized content is stored. 40.The method of claim 38 wherein said comparing comprises comparingcorresponding pixels of said images.
 41. The method of claim 40 whereinduring said comparing, at least one of intensity and color of saidcorresponding pixels is compared.
 42. The method of claim 38 furthercomprising associating a link to the stored one recognized object orstored composite recognized object.
 43. The method of claim 38 furthercomprising: superimposing said digital content on the associated storedone recognized object or stored composite recognized object.
 44. Themethod of claim 38 wherein each said at least one object is one of atextual object and a non-textual object.
 45. The method of claim 42further comprising activating said link in response to user input. 46.An interactive input system comprising: an input device capturing imagesof a three-dimensional (3D) input space; and computing structurecommunicating with said input device, said computing structure beingconfigured to: recognize at least one object in captured images; comparecaptured images to determine differences therebetween; when saiddifferences are greater than a difference threshold, merge therecognized objects to form a composite recognized object and store saidcomposite recognized object; when said differences are not greater thansaid difference threshold, store one of said recognized objects anddiscard the remaining recognized objects; and associate either saidstored composite recognized object or said stored one recognized objectwith digital content.
 47. The interactive input system of claim 46wherein the one recognized object that is stored is the recognizedobject having the most recognized content.
 48. The interactive inputsystem of claim 46 wherein said computing structure is configured tocompare corresponding pixels of said images.
 49. The interactive inputsystem of 48 wherein computing structure is configured to compare atleast one of intensity and color of said corresponding pixels.
 50. Theinteractive input system of claim 46 wherein said computing structure isfurther configured to associate a link to the stored one recognizedobject or stored composite recognized object.
 51. The interactive inputsystem of claim 46 wherein said computing structure is furtherconfigured to superimpose said digital content on the associated storedone recognized object or stored composite recognized object.
 52. Theinteractive input system of claim 46 wherein each said at least oneobject is one of a textual object and a non-textual object.
 53. Theinteractive input system of claim 50 wherein said computing structure isfurther configured to activate said link in response to user input. 54.A non-transitory computer-readable medium having computer-executableinstructions embodied thereon that, when executed by a computing device,facilitate a method comprising: capturing images of a three-dimensional(3D) input space; recognizing at least one object in each image;comparing a pair of said images to determine a difference therebetween;when said difference is greater than a difference threshold, mergingsaid recognized objects and associating digital content therewith; andwhen said difference is not greater than said difference threshold,maintaining at least one recognized object from only one of said imagesin said pair and associating digital content therewith.
 55. The methodof claim 54 wherein said maintained recognized object is the recognizedobject having the most recognized content.
 56. The method of claim 54wherein said comparing comprises comparing corresponding pixels of saidimages.
 57. The method of claim 54 further comprising associating a linkwith the maintained recognized object or the merged recognized objects.58. The method of claim 29 further comprising: superimposing saiddigital content on the associated maintained recognized object or mergedrecognized objects.
 59. The method of claim 54 wherein each said atleast one object is one of a textual object and a non-textual object.60. An interactive input system comprising: computing structure; and aninput device capturing an image of at least one physical object carryingrecognizable text within a three-dimensional (3D) input space andproviding image data to said computing structure, wherein said computingstructure processes the image data and is configured to: present saidimage on a display coupled to said computing structure; recognize atleast one object carried by the at least one physical object in the 3Dinput space; associate at least a portion of said recognized at leastone object with a link to digital content; receive user inputrepresenting activation of said link; and superimpose said digitalcontent on said image.
 61. The interactive input system of claim 60,wherein said digital content comprises at least one 3D digital object.62. A non-transitory computer-readable medium having computer-executableinstructions embodied thereon that, when executed by a computing device,facilitate a method comprising: presenting an image on a display coupledto computing structure; recognizing at least one object carried by atleast one physical object in a three-dimensional (3D) input space;associating at least a portion of said recognized at least one objectwith a link to digital content; receiving user input representingactivation of said link; and superimposing said digital content on saidimage.
 63. An image capturing apparatus comprising: computing structure;a camera device capturing images of a three-dimensional (3D) input spacecoupled to said computing structure, wherein said 3D input spacecomprises a two-dimensional (2D) plane; and light projection structurecoupled to said computing structure, said computing structure receivingimages captured by said input device, recognizing objects within saidimages, associating recognized objects with digital content, andprojecting said digital content to said 2D plane, wherein said digitalcontent is manipulatable on said 2D plane.
 64. The image capturingapparatus of claim 63, wherein said light projection structure is aprojector.
 65. (canceled)